The Shema

(ד) שְׁמַ֖ע יִשְׂרָאֵ֑ל יְהוָ֥ה אֱלֹהֵ֖ינוּ יְהוָ֥ה ׀ אֶחָֽד׃

(4) Hear, O Israel! The LORD is our God, the LORD alone.

Shema yisrael adonai eloheinu adonai ehad. The God-name yud-heh-vav-heh means being or becoming. Being is our God, Being is one. Or even, Becoming is our God. We have to discover what we will see. Becoming is a name for God that invites us not into a fixed image of what is true and right but into imagination.
Rabbi Jill Hammer, 2017

סידור אשכנז, ימי חול, תפילת שחרית, הכנה לתפילה, עול מלכות שמים ד׳

לְפִיכָךְ אֲנַֽחְנוּ חַיָּבִים לְהוֹדוֹת לְךָ וּלְשַׁבֵּחֲךָ וּלְפָאֶרְךָ וּלְבָרֵךְ וּלְקַדֵּשׁ וְלָֽתֶת־שֶֽׁבַח וְהוֹדָיָה לִשְׁמֶֽךָ: אַשְׁרֵֽינוּ מַה־טּוֹב חֶלְקֵֽנוּ וּמַה־נָּעִים גּוֹרָלֵֽנוּ וּמַה־יָּפָה יְרֻשָּׁתֵֽנוּ: אַשְׁרֵֽינוּ שֶׁאֲנַֽחְנוּ מַשְׁכִּימִים וּמַעֲרִיבִים עֶֽרֶב וָבֹֽקֶר וְאוֹמְ֒רִים פַּעֲמַֽיִם בְּכָל־יוֹם:

Siddur Ashkenaz, Weekday, Shacharit, Preparatory Prayers, Sovereignty of Heaven 4

Therefore, we are obligated to thank You, to praise You, and to glorify You; to bless, to sanctify, and to offer praise and thanks to Your Name. We are fortunate! How good is our portion! How pleasant is our destiny! How beautiful is our heritage! We are fortunate that we rise early and stay late - morning and evening - and twice daily say:

ספורנו על דברים ו׳:ד׳:א׳-ד׳

שמע ישראל התבונן והבן זה: ה' הנותן מציאות כל נברא. אלהינו. הוא נבחר מהנבדלים אצלנו אשר ממנו נקוה להשיג חפצינו בלי אמצעי ומצד היותו עליון בכחו הנורא הנה לו לבדו ראוי להשתחות ומצד שממנו תקותנו בלי אמצעי ראוי שאליו לבדו נתפלל ונעבוד: ה' אחד ובהיותו נותן המציאות אחר אפיסות מוחלט התבאר שאין נמצא זולתו מעין מציאותו ושהוא נבדל במין ממציאות עולם הנפסדים וממציאות עולם הגלגלים וממציאות עולם המלאכים באופן שהוא יחיד בעולמו הרביעי. וזה נראה שנרמז בהיות אות הדל"ת של אחד גדולה ובאות העי"ן של שמע הגדולה נרמז שראוי לפקוח עין ולהגדיל העי"ן בזה. ולזה אמרו ז"ל (ברכות פרק היה קורא) ובלבד שיאריך בדל"ת של אחד למען יכוין לזה:

Sforno on Deuteronomy 6:4:1-4

שמע ישראל, listen Israel with your mind open; 'ה, He is the One Who is responsible for the existence of a physical universe and our globe, the only part of it on which physical life exists. אלוקינו, He is the choicest of all the abstract forces assigned to supervise the conduct of human beings, and even inert creatures. From Him we yearn for assistance in helping us to achieve our purpose on earth. We do not turn to any intermediary. He alone is fit to have prayers addressed to. ה' אחד; seeing that He created all phenomena in this universe, celestial or terrestrial out of a total void, it is logically impossible for there to be another phenomenon representing an existence independent of Him. It also makes him basically different, unique, for all things created by Him are by definition potentially terminal, transient existences. He is absolutely unique in the world based on four basic raw materials, water, fire, earth, air. This idea appears to be hinted at in the letter ד=4 in the word אחד which is written larger than usual and the letter ע in the word שמע which is also written in larger than normal script, suggesting that we should use our eyes to take note of these concepts, the “testimony, עד” that this is so. This is why our sages said that we must draw out the word אחד when reciting it so as to give us time to reflect on the full meaning of the verse.

משנה תורה, הלכות קריאת שמע ב׳:א׳

הַקּוֹרֵא אֶת שְׁמַע וְלֹא כִּוֵּן לִבּוֹ בְּפָסוּק רִאשׁוֹן שֶׁהוּא (דברים ו ד) ״שְׁמַע יִשְׂרָאֵל״ לֹא יָצָא יְדֵי חוֹבָתוֹ וְהַשְּׁאָר אִם לֹא כִּוֵּן לִבּוֹ יָצָא. אֲפִלּוּ הָיָה קוֹרֵא בַּתּוֹרָה כְּדַרְכּוֹ אוֹ מַגִּיהַּ אֶת הַפָּרָשִׁיּוֹת הָאֵלּוּ בְּעוֹנַת קְרִיאָה יָצָא וְהוּא שֶׁכִּוֵּן לִבּוֹ בְּפָסוּק רִאשׁוֹן:

Mishneh Torah, Reading the Shema 2:1

One who reads the Shema and does not concentrate his mind while reciting the first verse—"Hear, O Israel, the Lord, our God, the Lord is One," has not fulfilled his duty. As to the remaining verses, if he did not concentrate his mind (while reciting them), he has nevertheless fulfilled his duty. Even if he was reading the Torah in his usual course of study or examining these sections in a scroll (to ensure correctness), and read them at the prescribed time, he has fulfilled his duty, provided however that he concentrated his mind while reciting the First Verse.

The first thing that you should cause your soul to hold fast onto is that, while reciting the Shema‘ prayer, you should empty your mind of everything and pray thus. You should not content yourself with being intent while reciting the first verse of Shema‘ and saying the first benediction.
RamBam, The Guide for the Perplexed

We are commanded to carry out specific rituals, such as reciting twice a day "Hear O Israel ... " or setting of the tefillin on arm and head. Are we merely commanded to recite "Hear O Israel ... God is One," and not to hear? Is one's setting of the tefillin on head and arm merely a matter of external performance ? No religious act is properly fulfilled unless it is done with a willing heart and a craving soul. You cannot worship Him with your body, if you do not know how to worship Him in your soul. The relationship between deed and inner devotion must be understood, as we shall see, in terms of polarity.
Abraham Joshua Heschel, God in Search of Man

משנה תורה, הלכות קריאת שמע ב׳:ב׳

כָּל אָדָם קוֹרִין כְּדַרְכָּן בֵּין עוֹמְדִין בֵּין מְהַלְּכִין בֵּין שׁוֹכְבִין בֵּין רוֹכְבִין עַל גַּבֵּי בְּהֵמָה. וְאָסוּר לִקְרוֹת קְרִיאַת שְׁמַע וְהוּא מֻטָּל וּפָנָיו טוּחוֹת בַּקַּרְקַע אוֹ מֻשְׁלָךְ עַל גַּבּוֹ וּפָנָיו לְמַעְלָה. אֲבָל קוֹרֵא הוּא וְהוּא שׁוֹכֵב עַל צִדּוֹ. וְאִם הָיָה בַּעַל בָּשָׂר הַרְבֵּה וְאֵינוֹ יָכוֹל לְהִתְהַפֵּךְ עַל צִדּוֹ אוֹ שֶׁהָיָה חוֹלֶה נוֹטֶה מְעַט לְצִדּוֹ וְקוֹרֵא:

Mishneh Torah, Reading the Shema 2:2

Everyone may read the Shema in the ordinary postures—standing, walking, lying down or riding on an animal. It is forbidden to read the Shema, lying down prone with face to the ground, or lying on the back with face looking up. But one may read it while lying on one's side. An extremely corpulent person who is unable to turn on his side or one who is sick should slightly turn on his side and then recite the Shema.

ברכות ה׳ א:ב׳

אָמַר רַבִּי לֵוִי בַּר חָמָא, אָמַר רַבִּי שִׁמְעוֹן בֶּן לָקִישׁ: לְעוֹלָם יַרְגִּיז אָדָם יֵצֶר טוֹב עַל יֵצֶר הָרַע, שֶׁנֶּאֱמַר: ״רִגְזוּ וְאַל תֶּחֱטָאוּ״ אִם נִצְּחוֹ — מוּטָב, וְאִם לָאו — יַעֲסוֹק בַּתּוֹרָה, שֶׁנֶּאֱמַר: ״אִמְרוּ בִלְבַבְכֶם״. אִם נִצְּחוֹ — מוּטָב, וְאִם לָאו — יִקְרָא קְרִיאַת שְׁמַע, שֶׁנֶּאֱמַר: ״עַל מִשְׁכַּבְכֶם״. אִם נִצְּחוֹ — מוּטָב, וְאִם לָאו — יִזְכּוֹר לוֹ יוֹם הַמִּיתָה, שֶׁנֶּאֱמַר: ״וְדֹמּוּ סֶלָה״.

Berakhot 5a:2

Incidental to the verse, “Tremble, and do not sin,” the Gemara mentions that Rabbi Levi bar Ḥama said that Rabbi Shimon ben Lakish said: One should always incite his good inclination against his evil inclination, i.e., that one must constantly struggle so that his evil inclination does not lead him to transgression, as it is stated: "Tremble, and do not sin."
If one succeeds and subdues his evil inclination, excellent, but if he does not succeed in subduing it, he should study Torah, as alluded to in the verse: “Say to your heart.”
If he subdues his evil inclination, excellent; if not, he should recite Shema, which contains the acceptance of the yoke of God, and the concept of reward and punishment, as it is stated in the verse: “Upon your bed,” which alludes to Shema, where it says: “When you lie down.”
If he subdues his evil inclination, excellent; if not, he should remind himself of the day of death, whose silence is alluded to in the continuation of the verse: “And be still, Selah.”

ברכות ה׳ א:ה׳

וְאָמַר רַבִּי יִצְחָק: כׇּל הַקּוֹרֵא קְרִיאַת שְׁמַע עַל מִטָּתוֹ — מַזִּיקִין בְּדֵילִין הֵימֶנּוּ. שֶׁנֶּאֱמַר: ״וּבְנֵי רֶשֶׁף יַגְבִּיהוּ עוּף״, וְאֵין ״עוּף״ אֶלָּא תּוֹרָה, שֶׁנֶּאֱמַר: ״הֲתָעִיף עֵינֶיךָ בּוֹ וְאֵינֶנּוּ״. וְאֵין ״רֶשֶׁף״ אֶלָּא מַזִּיקִין, שֶׁנֶּאֱמַר: ״מְזֵי רָעָב וּלְחֻמֵי רֶשֶׁף וְקֶטֶב מְרִירִי״.

Berakhot 5a:5

And Rabbi Yitzḥak said: Anyone who recites Shema upon his bed, demons stay away from him. This is alluded to, as it is stated: “But man is born into trouble, and the sparks [reshef ] fly [uf ] upward” (Job 5:7). The verse is explained: The word fly [uf ] means nothing other than Torah, as Torah is difficult to grasp and easy to lose, like something that floats away, as it is stated: “Will you set your eyes upon it? It is gone; for riches certainly make themselves wings, like an eagle that flies into the heavens” (Proverbs 23:5). The word “sparks” means nothing other than demons, as it is stated: “Wasting of hunger, and the devouring of the sparks [reshef] and bitter destruction [ketev meriri], and the teeth of beasts I will send upon them, with the venom of crawling things of the dust” (Deuteronomy 32:24). Here we see reshef listed along with ketev meriri, both of which are understood by the Sages to be names of demons.

Arthur Green, Judaism's Ten Best Ideas (pg. 60)
This line is addressed to the community: “Hear O Israel”—Listen, Jews!—“Y-H-W-H is our God; Y-H-W-H is one!” How are we to understand Judaism’s great proclamation of our monotheistic faith? Let us begin by asking a functional question, the most important question regarding human behavior. What difference does monotheism make? One god, ten gods, a thousand—so what? We Jews seem to put so much store in the fact that we believe in one rather than many gods. Why? What is the payoff of the great monotheistic revolution? The only value of monotheism is to make you realize that all beings, every creature—and that means the rock and the blade of grass as well as your pet lizard and your annoying neighbor next door—are all one in origin. You come from the same place. You were created in the same great act of love, God bestowing God’s own grace on every creature that would ever come to be. Therefore—and this is the key line, the only one that really counts—treat them that way!

משנה תורה, הלכות יסודי התורה א׳:ז׳

אֱלוֹהַּ זֶה אֶחָד הוּא וְאֵינוֹ שְׁנַיִם וְלֹא יֶתֶר עַל שְׁנַיִם. אֶלָּא אֶחָד. שֶׁאֵין כְּיִחוּדוֹ אֶחָד מִן הָאֲחָדִים הַנִּמְצָאִים בָּעוֹלָם. לֹא אֶחָד כְּמִין שֶׁהוּא כּוֹלֵל אֲחָדִים הַרְבֵּה. וְלֹא אֶחָד כְּגוּף שֶׁהוּא נֶחְלָק לְמַחְלָקוֹת וְלִקְצָווֹת. אֶלָּא יִחוּד שֶׁאֵין יִחוּד אַחֵר כְּמוֹתוֹ בָּעוֹלָם. אִלּוּ הָיוּ אֱלֹהוּת הַרְבֵּה הָיוּ גּוּפִין וּגְוִיּוֹת. מִפְּנֵי שֶׁאֵין הַנִּמְנִים הַשָּׁוִין בִּמְצִיאוּתָן נִפְרָדִין זֶה מִזֶּה אֶלָּא בִּמְאֹרָעִין שֶׁיֶּאֶרְעוּ בַּגּוּפוֹת וְהַגְּוִיּוֹת. וְאִלּוּ הָיָה הַיּוֹצֵר גּוּף וּגְוִיָּה הָיָה לוֹ קֵץ וְתַכְלִית שֶׁאִי אֶפְשָׁר לִהְיוֹת גּוּף שֶׁאֵין לוֹ קֵץ. וְכָל שֶׁיֵּשׁ לְגוּפוֹ קֵץ וְתַכְלִית יֵשׁ לְכֹחוֹ קֵץ וָסוֹף. וֵאלֹהֵינוּ בָּרוּךְ שְׁמוֹ הוֹאִיל וְכֹחוֹ אֵין לוֹ קֵץ וְאֵינוֹ פּוֹסֵק שֶׁהֲרֵי הַגַּלְגַּל סוֹבֵב תָּמִיד. אֵין כֹּחוֹ כֹּחַ גּוּף. וְהוֹאִיל וְאֵינוֹ גּוּף לֹא יֶאֶרְעוּ לוֹ מְאֹרְעוֹת הַגּוּפוֹת כְּדֵי שֶׁיְּהֵא נֶחְלָק וְנִפְרָד מֵאַחֵר. לְפִיכָךְ אִי אֶפְשָׁר שֶׁיִּהְיֶה אֶלָּא אֶחָד. וִידִיעַת דָּבָר זֶה מִצְוַת עֲשֵׂה שֶׁנֶּאֱמַר (דברים ו ד) "ה' אֱלֹהֵינוּ ה' אֶחָד":

Mishneh Torah, Foundations of the Torah 1:7

this doctrine of Monotheism is a mandatory commandment, saying: "The Lord our God is One God" (Deut. 6.4).

משנה תורה, הלכות יסודי התורה א׳:א׳

(א) יְסוֹד הַיְסוֹדוֹת וְעַמּוּד הַחָכְמוֹת לֵידַע שֶׁיֵּשׁ שָׁם מָצוּי רִאשׁוֹן. וְהוּא מַמְצִיא כָּל נִמְצָא. וְכָל הַנִּמְצָאִים מִשָּׁמַיִם וָאָרֶץ וּמַה שֶּׁבֵּינֵיהֶם לֹא נִמְצְאוּ אֶלָּא מֵאֲמִתַּת הִמָּצְאוֹ:

Mishneh Torah, Foundations of the Torah 1:1

(1) The foundation of foundations and firmest pillar of all wisdom is, To know that there is a First Being, that He caused all beings to be, and that all beings from heaven and earth, and from between them, could not be save for the truth of His Own Being.

רש"י על דברים ו׳:ד׳:א׳

(א) ה' אלהינו ה' אחד. ה' שֶׁהוּא אֱלֹהֵינוּ עַתָּה, וְלֹא אֱלֹהֵי הָאֻמּוֹת, הוּא עָתִיד לִהְיוֹת ה' אֶחָד, שֶׁנֶּאֱמַר (צפ' ח') כִּי אָז אֶהְפֹּךְ אֶל עַמִּים שָׂפָה בְרוּרָה לִקְרֹא כֻלָּם בְּשֵׁם ה', וְנֶאֱמַר (זכריה י"ד) בַּיּוֹם הַהוּא יִהְיֶה ה' אֶחָד וּשְׁמוֹ אֶחָד (ע' ספרי):

Rashi on Deuteronomy 6:4:1

(1) ה׳ אלהינו ה' אחד means, The Lord who is now our God and not the God of the other peoples of the world, He will at some future time be the One (sole) ה׳, as it is said, (Zephaniah 3:9) “For then I will turn to the peoples a pure language that they may all call upon the name of the Lord", and it is further said, (Zechariah 14:9) “In that day shall the Lord be One (אחד) and His name One" (cf. Sifrei Devarim 31:10).

ספורנו על דברים ו׳:ד׳:א׳-ג׳

(א) שמע ישראל התבונן והבן זה: (ב) ה' הנותן מציאות כל נברא. (ג) אלהינו. הוא נבחר מהנבדלים אצלנו אשר ממנו נקוה להשיג חפצינו בלי אמצעי ומצד היותו עליון בכחו הנורא הנה לו לבדו ראוי להשתחות ומצד שממנו תקותנו בלי אמצעי ראוי שאליו לבדו נתפלל ונעבוד:

Sforno on Deuteronomy 6:4:1-3

(1) שמע ישראל, listen Israel with your mind open; (2) 'ה, He is the One Who is responsible for the existence of a physical universe and our globe, the only part of it on which physical life exists. (3) אלוקינו, He is the choicest of all the abstract forces assigned to supervise the conduct of human beings, and even inert creatures. From Him we yearn for assistance in helping us to achieve our purpose on earth. We do not turn to any intermediary. He alone is fit to have prayers addressed to.

רש"י על דברים ו׳:ד׳:א׳

Rashi on Deuteronomy 6:4:1

דעת זקנים על דברים ו׳:ד׳:א׳

(ד) שמע ישראל ה' אלקינו ה' אחד. בלא שלשה הזכרות אי אפשר שאם אמר שמע ישראל ה' אחד כל אומה ואומה אומרת על עכו"ם שלהם שהוא אחד כשהוא אומר אלקינו יודע שעל אלקי ישראל הוא מדבר ואם היינו אומרים ה' אחד משמע אלקינו אחד מן האלהות וכ"ש אם היינו אומרים אלקינו אחד אבל כשאנו כופלים ה"ק ה' שהוא אדון שלנו הוא אחד באדנות ואין עוד מלבדו. וצריך לומר אל מלך נאמן קודם שמע ישראל לפי שבשלש תיבות הללו עם בשכמל"ו תמצא בק"ש רמ"ח תיבות כנגד רמ"ח אברים וכל האומר רמ"ח תיבות שבק"ש כתקנן הקב"ה משמר רמ"ח אבריו וזש"ה שמור מצותי וחיה אמר הקב"ה שמור את שלי ואני אשמור את שלך. א"ר שמעון בן חלפתא משל למלך שהיה לו כרם ביהודה ודירתו בגליל ולאחד יש לו כרם בגליל ודירתו ביהודה בכל שנה ושנה צריך זה שביהודה לילך לגליל וזה שבגליל לילך ליהודה לפרנס כל אחד צרכי כרמו לימים פגעו זה בזה אמרו למה אנו מטריחין אני אפרנס כרמך שבעירי ואתה תפרנס כרמי שבעירך והזהר בה שאם אתה משמר היטב את שלי אני אשמור היטב את שלך:

Da'at Zekenim on Deuteronomy 6:4:1

(4) שמע ישראל ה' אלוקינו ה' אחד, “Hear, O Israel, the Lord is our G’d, the Lord alone.” This verse would not be complete unless G’d’s name had appeared in it three times. If the Torah had only written: שמע ישראל ה' אחד, “Hear Israel, the Lord is one,” every other nation in the world would have claimed that their national deity was also unique for them. By adding the word: אלוקינו, “our G’d,” every reader would know that the subject is the G’d of Israel. If we would only say: “the Lord our G’d is one,” the impression would be left that He is one of a number of deities. The correct translation of the way Moses described G’d in our verse is: “the Lord Who is our Master is unique as a Master, and there is none beside Him.” When reciting this line in our prayers it is necessary to introduce this prayer with the words: א-ל מלך נאמן, “G’d who is a true king.” The reason that the authors of the prayer book have seen fit to add these three words is that by adding them the three paragraphs of this prayer including the line ברוך שם כבוד מלכותו, “blessed be the glory of His Kingdom,” total 248 words, a number which equals the 248 limbs in our bodies. This is hinted at by Solomon in Proverbs 4,4: שמר מצותי וחיה “Keep My commandments and you will live.” G’d is portrayed as saying that if you (Israel) keep My commandments, I will keep you alive.” Rabbi Shimon ben Chalafta explained this concept by means of a parable: a king possessed a vineyard in the central part of the land of Israel, whereas his residence was in the northern part of the country. Another king possessed a vineyard in the northern part of Israel, whereas his residence was in the central part of the country. Each king had to travel at least once a year from his residence to his vineyard to make sure the vineyard was being tended properly. Eventually, these two kings met one another and each complained to the other about the inconvenience of having to visit his vineyard every year. They made an agreement that each king would take care of the other’s vineyard, an arrangement that saved each of them a lot of time and inconvenience.

משנה תורה, הלכות יסודי התורה א׳:ז׳

אֱלוֹקַּ זֶה אֶחָד הוּא וְאֵינוֹ שְׁנַיִם וְלֹא יֶתֶר עַל שְׁנַיִם. אֶלָּא אֶחָד. שֶׁאֵין כְּיִחוּדוֹ אֶחָד מִן הָאֲחָדִים הַנִּמְצָאִים בָּעוֹלָם. לֹא אֶחָד כְּמִין שֶׁהוּא כּוֹלֵל אֲחָדִים הַרְבֵּה. וְלֹא אֶחָד כְּגוּף שֶׁהוּא נֶחְלָק לְמַחְלָקוֹת וְלִקְצָווֹת. אֶלָּא יִחוּד שֶׁאֵין יִחוּד אַחֵר כְּמוֹתוֹ בָּעוֹלָם. אִלּוּ הָיוּ אֱלֹהוּת הַרְבֵּה הָיוּ גּוּפִין וּגְוִיּוֹת. מִפְּנֵי שֶׁאֵין הַנִּמְנִים הַשָּׁוִין בִּמְצִיאוּתָן נִפְרָדִין זֶה מִזֶּה אֶלָּא בִּמְאֹרָעִין שֶׁיֶּאֶרְעוּ בַּגּוּפוֹת וְהַגְּוִיּוֹת. וְאִלּוּ הָיָה הַיּוֹצֵר גּוּף וּגְוִיָּה הָיָה לוֹ קֵץ וְתַכְלִית שֶׁאִי אֶפְשָׁר לִהְיוֹת גּוּף שֶׁאֵין לוֹ קֵץ. וְכָל שֶׁיֵּשׁ לְגוּפוֹ קֵץ וְתַכְלִית יֵשׁ לְכֹחוֹ קֵץ וָסוֹף. וֵאלֹקֵינוּ בָּרוּךְ שְׁמוֹ הוֹאִיל וְכֹחוֹ אֵין לוֹ קֵץ וְאֵינוֹ פּוֹסֵק שֶׁהֲרֵי הַגַּלְגַּל סוֹבֵב תָּמִיד. אֵין כֹּחוֹ כֹּחַ גּוּף. וְהוֹאִיל וְאֵינוֹ גּוּף לֹא יֶאֶרְעוּ לוֹ מְאֹרְעוֹת הַגּוּפוֹת כְּדֵי שֶׁיְּהֵא נֶחְלָק וְנִפְרָד מֵאַחֵר. לְפִיכָךְ אִי אֶפְשָׁר שֶׁיִּהְיֶה אֶלָּא אֶחָד. וִידִיעַת דָּבָר זֶה מִצְוַת עֲשֵׂה שֶׁנֶּאֱמַר (דברים ו ד) "ה' אֱלֹקֵינוּ ה' אֶחָד":

Mishneh Torah, Foundations of the Torah 1:7

This G!d is One G!d; G!d is neither two nor more than two but One to whose Unity there is no comparison among the individual units in the universe; not like the unit of a genus which embraces many individual units, nor like the unit of a body which is divisible into parts and particles, but a Unit to Whose Unity no other unit in the universe is like. Supposing that there are many deities is equivalent to an admission that they are corporeal, because like individual beings do not differ save in chance traits characteristic of bodies and material things only. Thus supposing the Creator to be corporeal and material would force a conclusion that G!d is finite, for, it is impossible to imagine a body which does not end in dissolution; but our G!d, blessed is G!d's Name! beholding that G!d's power is infinite and uninterrupted, for lo, the universal sphere continues to revolve forever. G!d's power is positively not a physical power. And, because G!d is Incorporeal, none of the chance traits, characteristic of bodies, so as to be divisible or an offshoot of another being, can be attributed to G!d. Therefore, the impossibility for G!d to be but One. And, the knowledge of this doctrine of Monotheism is a mandatory commandment, saying: "ה' our G!d is One G!d" (Deut. 6.4).

The Language of Truth: The Torah Commentary of the Sefat Emet, Rabbi Yehudah Leib Alter of Ger, translated and interpreted by Arthur Green (Philadelphia: JPS, 1998), 289-90.
S’fat Emet: “You shall love YHWH your God" (Deut. 6:5). The Midrash quotes: "Whom do I have in heaven; I desire none alongside you in earth" (Ps. 73:25). This means one should want nothing but God.
“With all your soul"—"with every single soul-breath that God has created in you." And the meaning of "be-khol levavekha" is not "with all your heart," as most people interpret it. But rather, we need to become aware that each feeling we have is only the life-force that comes from God. "A person does not bang his finger below unless it is decreed from above"; we are but "the axe in the woodchopper's hand."
This is the meaning of "YHWH is one." It goes beyond the fact that there is just one God; there is YI-IWH and nothing else. Every thing that exists is only His blessed life, but it is hidden. The same is true of His blessed will. Therefore, the love of God has to be in every feeling a person has. This is "all your heart.” (5:18)
Green: Here we have the mystical claim of Hasidism in its most undiluted form. Since nothing but God is real, we should both seek and find nothing but God in all of our lives. Every feeling and emotion, every want and desire, come from nowhere other than the being and will of God. To worship God with "all your heart" requires recognizing this truth and living in response to it.
How would we begin to make this teaching real in our religious and emotional lives? It would require two steps: a great opening and a great directing. The first step is one of radical self-acceptance and inclusion. "I will stop fighting off my thoughts, stop picking and choosing among my desires. All of them, even those I like least, have their root in God, for there is no other root." The second step is that of directing and uplifting each of these thoughts and desires. Try addressing each of your desires this way: "The game is up, O desire. You can't fool me any more. I know that you too come from God, even if in fallen form. Now I will take you back to your root, using the energy you arouse in me to give to God in yet a more whole way."
This teaching does not answer for us the critical question of which desires or emotions we may act upon, celebrating God's presence in the fulfillment of desire, and which we must hold back, worshipping God with transformed desire alone. The spiritual life requires a proper balancing between these two; it is the critical role of halakhah—whether the old or a new form—to offer us guidance as to where those lines are drawn.

From Rabbi Shefa Gold, "V'Etchanan" at https://www.rabbishefagold.com/vetchanan/
“Listen God-wrestler, YHVH is your God, YHVH is One.” The words of the Sh’ma pierce through the veils of illusion. These words have the power to awaken us from our trance of separation that obscures the truth that there is Only God...
WHEN GOD TELLS MOSES to climb the mountain and lift his eyes, we are being invited to receive a glimpse of Unity. From the summit of this mountain, everything that we thought separate, all of the opposites that have warred within us, are suddenly united. It is all Echad — “One.” Then the fullness of Love can flow. Then, “You shall love God with all your heart and all your soul and all your might.” When we experience the knowledge of the Unity beyond Duality, it takes root inside us, and we become lovers of the highest order.

From Rabbi Jill Hammer, "Va'Etchanan 5778", at https://ajr.edu/2018/07/vaethanan-5778/
Shema yisrael adonai eloheinu adonai ehad. The God-name yud-heh-vav-heh means being or becoming. Being is our God, Being is one. Or even, Becoming is our God. We have to discover what we will see. Becoming is a name for God that invites us not into a fixed image of what is true and right but into imagination.
The Zohar, a foundational work of Jewish mysticism, has an interesting definition of oneness. It teaches that each time we say the Shema, we bring together the faces of God through the combination of the divine names. The Shema is a declaration of oneness that is also a resolution of duality. Listen to the Zohar’s translation: Hear O Israel, the Holy One and the Shekhinah are unified, divinity is at one. In this reading, the Shema isn’t a declaration of a static reality, it’s a theurgic action, a ritual in which we create divine oneness by bringing together God’s faces into a whole. We are actually helping to create oneness by imagining oneness as we say the Shema. This oneness implies not aloneness but togetherness, joining, union— a union we can be part of. A union that includes everyone. The Hasidic thinker Shneur Zalman of Liadi says that the Shema describes a hidden reality in which there is nothing but God, a reality where all being is one.
So of course we read this parashah at the season of Tu b’Av. The fifteenth of Av, this Thursday night, which falls a week after Tisha b’Av, is a folk Israelite festival. It’s mentioned as a grape harvest dancing holiday in the Bible, and in the Talmud it’s mentioned as a holiday in which unmarried women put on white clothes and go out to dance in the fields, and men and the whole community go out to watch this dance, so the women may attract the attention of a potential relationship partner.
Two things about the white clothes: one, they have to be dunked in a mikveh, which means they are holy. Two: the clothes have to be borrowed from someone else. This means the holy dancers cannot be easily recognized in terms of tribe or social status. You have to know who they are, not by what they are wearing or where they live, but by discovering them in motion. This reminds us that we cannot find God in people when we think we know them by their traits or demographics. We have to know them through encounter.

רמב"ן על דברים ו׳:ד׳:א׳

... ואתה צריך להתבונן בזה כי שנה הכתוב כאן לומר ה' אלהינו ולא אמר אלהיך כמו שאומר בכל מקום שמע ישראל אתה עובר היום וגו' כי ה' אלהיך (להלן ט א ג) שמע ישראל אתם קרבים היום וגו' כי ה' אלהיכם (להלן כ ג ד) וכן בכל הפרשיות שידבר עם ישראל יזכיר ה' אלהיכם או ה' אלהיך וגם בכאן אמר ואהבת את ה' אלהיך אבל הזכיר ביחוד ה' אלהינו כי עשה עם משה את הגדולות ואת הנוראות לעשות לו שם תפארת ה תורה:

Ramban on Deuteronomy 6:4:1

...Now you must contemplate [the fact] that Scripture changed [the normal usage] here by saying the Eternal ‘our’ G-d and did not state “thy” G-d as it says everywhere else: Hear, O Israel: thou art to pass over the Jordan this day etc. Know therefore this day, that the Eternal ‘thy’ G-d etc.; Hear, O Israel, ye draw nigh this day unto battle etc. for the Eternal ‘your’ G-d is He that goeth with you. And so also in all sections where [Moses] spoke to Israel he mentioned “the Eternal your G-d” or “the Eternal thy G-d,” and even here [in this very section] he said, And thou shalt love the Eternal ‘thy’ G-d. However, in this declaration of the Unity [of G-d] Moses said, the Eternal ‘our’ G-d because He had done great and awesome things with Moses to make Himself a glorious Name [therefore Moses said “our G-d,” for had he said “your G-d,” he might have appeared to exclude himself from this declaration of Unity]. ...