Eikev - Circumcision of the Heart
(יב) וְעַתָּה֙ יִשְׂרָאֵ֔ל מָ֚ה יְהוָ֣ה אֱלֹהֶ֔יךָ שֹׁאֵ֖ל מֵעִמָּ֑ךְ כִּ֣י אִם־לְ֠יִרְאָה אֶת־יְהוָ֨ה אֱלֹהֶ֜יךָ לָלֶ֤כֶת בְּכָל־דְּרָכָיו֙ וּלְאַהֲבָ֣ה אֹת֔וֹ וְלַֽעֲבֹד֙ אֶת־יְהוָ֣ה אֱלֹהֶ֔יךָ בְּכָל־לְבָבְךָ֖ וּבְכָל־נַפְשֶֽׁךָ׃ (יג) לִשְׁמֹ֞ר אֶת־מִצְוֺ֤ת יְהוָה֙ וְאֶת־חֻקֹּתָ֔יו אֲשֶׁ֛ר אָנֹכִ֥י מְצַוְּךָ֖ הַיּ֑וֹם לְט֖וֹב לָֽךְ׃ (יד) הֵ֚ן לַיהוָ֣ה אֱלֹהֶ֔יךָ הַשָּׁמַ֖יִם וּשְׁמֵ֣י הַשָּׁמָ֑יִם הָאָ֖רֶץ וְכָל־אֲשֶׁר־בָּֽהּ׃ (טו) רַ֧ק בַּאֲבֹתֶ֛יךָ חָשַׁ֥ק יְהוָ֖ה לְאַהֲבָ֣ה אוֹתָ֑ם וַיִּבְחַ֞ר בְּזַרְעָ֣ם אַחֲרֵיהֶ֗ם בָּכֶ֛ם מִכָּל־הָעַמִּ֖ים כַּיּ֥וֹם הַזֶּה׃ (טז) וּמַלְתֶּ֕ם אֵ֖ת עָרְלַ֣ת לְבַבְכֶ֑ם וְעָ֨רְפְּכֶ֔ם לֹ֥א תַקְשׁ֖וּ עֽוֹד׃ (יז) כִּ֚י יְהוָ֣ה אֱלֹֽהֵיכֶ֔ם ה֚וּא אֱלֹהֵ֣י הָֽאֱלֹהִ֔ים וַאֲדֹנֵ֖י הָאֲדֹנִ֑ים הָאֵ֨ל הַגָּדֹ֤ל הַגִּבֹּר֙ וְהַנּוֹרָ֔א אֲשֶׁר֙ לֹא־יִשָּׂ֣א פָנִ֔ים וְלֹ֥א יִקַּ֖ח שֹֽׁחַד׃ (יח) עֹשֶׂ֛ה מִשְׁפַּ֥ט יָת֖וֹם וְאַלְמָנָ֑ה וְאֹהֵ֣ב גֵּ֔ר לָ֥תֶת ל֖וֹ לֶ֥חֶם וְשִׂמְלָֽה׃ (יט) וַאֲהַבְתֶּ֖ם אֶת־הַגֵּ֑ר כִּֽי־גֵרִ֥ים הֱיִיתֶ֖ם בְּאֶ֥רֶץ מִצְרָֽיִם׃

(12) And now, O Israel, what does YHVH your God demand of you? Only this: to revere YHVH your God, to walk only in God's paths, to love God, and to serve YHVH your God with all your heart and soul, (13) keeping YHVH's commandments and laws, which I enjoin upon you today, for your good. (14) Mark, the heavens to their uttermost reaches belong to YHVH your God, the earth and all that is on it! (15) Yet it was to your ancestors that YHVH was drawn in love for them, so that God chose you, their lineal descendants, from among all peoples—as is now the case. (16) Cut away, therefore, the thickening about your hearts and stiffen your necks no more. (17) For YHVH your God is God supreme, the great, the mighty, and the awesome God, who shows no favor and takes no bribe, (18) but upholds the cause of the fatherless and the widow, and befriends the stranger, providing him with food and clothing.— (19) You too must befriend the stranger, for you were strangers in the land of Egypt.

(א) ערלת לבבכם. אֹטֶם לְבַבְכֶם וְכִסּוּיוֹ:

(1) ערלת לבבכם [YOU SHALL CIRCUMCISE] THE FORESKIN OF YOUR HEART — This means: ye shall remove the closure and cover that is on your hearts, [which prevent My words gaining entrance to them] (cf. Rashi on Exodus 6:12 and Leviticus 19:23).

ומלתם את ערלת לבבכם. פחיתות המדות והיצירה מגדר השוייתם יקרא ערלה, כי כל ערלה תוספת חסרון, וכל מי שהוא ערל לב אין בו כח לקבל המושכלות ולהבין דרך האמת.
. ומלתם את ערלת לבבכם, “You shall ‘circumcise’ the foreskin surrounding your heart.“ The term ערלה is applied when the Torah or the prophet wants to describe a negative character trait, a trait which inhibits development of a personality to its full potential. Anyone who is burdened with such an impediment to his personality development cannot truly embrace the commandments we know as the מצות המושכלות and to understand their true value.
(יב) וַיְדַבֵּ֣ר מֹשֶׁ֔ה לִפְנֵ֥י יְהוָ֖ה לֵאמֹ֑ר הֵ֤ן בְּנֵֽי־יִשְׂרָאֵל֙ לֹֽא־שָׁמְע֣וּ אֵלַ֔י וְאֵיךְ֙ יִשְׁמָעֵ֣נִי פַרְעֹ֔ה וַאֲנִ֖י עֲרַ֥ל שְׂפָתָֽיִם׃ (פ)

(12) But Moses appealed to YHVH saying, “The Israelites would not listen to me; how then should Pharaoh heed me, a man of impeded speech!”

(י) עַל־מִ֨י אֲדַבְּרָ֤ה וְאָעִ֙ידָה֙ וְיִשְׁמָ֔עוּ הִנֵּה֙ עֲרֵלָ֣ה אָזְנָ֔ם וְלֹ֥א יוּכְל֖וּ לְהַקְשִׁ֑יב הִנֵּ֣ה דְבַר־יְהוָ֗ה הָיָ֥ה לָהֶ֛ם לְחֶרְפָּ֖ה לֹ֥א יַחְפְּצוּ־בֽוֹ׃

(10) To whom shall I speak, Give warning that they may hear? Their ears are blocked And they cannot listen. See, the word of YHVH has become for them An object of scorn; they will have none of it.

The greatest hindrance to knowledge is our adjustment to conventional, to mental cliches. Wonder or radical amazement, the state of maladjustment to words and notions is, therefore, a prerequisite for an authentic awareness of that which is. Rabbi Abraham Joshua Heschel, Man Is Not Alone.

Scholars have long struggled to understand just what the heart (lev) symbolizes in biblical thinking. Some interpreters insist that in the Torah, the heart is "considered, not the seat of feelings, but of intelligence," in which case what the Torah asks for in our verse is for Israel to open its mind. Others assert that is is "the organ of volition" in which case what is called for is a conversion of the will. More convincing, in my view, is a more expansive interpretation, according to which "the heart in Hebrew thought is the preeminent metaphor for the inner being of a person, the seat of intelligence; the seat of emotions, and the seat of volition, i.e., the will." Moses thus demands that the people totally transform their inner lives, so that they will now respond to God's command with loyalty, readiness, and faithfulness. As Bible scholar Richard Nelson explains, "circumcising the heart is a metaphor for a radical, interior, renewal that makes love and obedience fully possible." Rabbi Shai Held; Will and Grace Or: Who Will Circumcise the Heart

(א) ומלתם את ערלת לבבכם אם כן ראוי שתסירו את ערלת שכלכם והוא שתתבוננו להסיר כל טעות מוליד דעות כוזבות:
(1) ומלתם את ערלת לבבכם, therefore, it is appropriate that you remove the “foreskin,” prejudices with which your intelligence is afflicted, so that you will realise the errors you have made in your world outlook based on false premises.
וּכְשֶׁחוֹשֵׁב מַחֲשָׁבוֹת רָעוֹת, הוּא מְטַמְטֵם הַלֵּב, בִּבְחִינַת עָרְלַת לֵב, וּמְקַלְקֵל אֶת הַבְּרִיאָה, הַיְנוּ הַחָכְמָה שֶׁבַּלֵּב. כִּי הַיֵּצֶר הָרָע הוּא טִפְּשׁוּת הַלֵּב, כְּמוֹ שֶׁכָּתוּב (דברים י׳:ט״ז): וּמַלְתֶּם אֶת עָרְלַת לְבַבְכֶם, וְתַרְגּוּמוֹ: יָת טִפְּשׁוּת לִבְּכוֹן. וְטִפְּשׁוּת הוּא קִלְקוּל הַבְּרִיאָה, שֶׁהִיא עַל־יְדֵי הַחָכְמָה.
But when a person thinks evil thoughts, he clogs up the heart in the aspect of a foreskinned heart, and he spoils the creation—i.e., the Chokhmah in the heart. This is because the evil inclination is the foolishness of the heart, as it is written (Deuteronomy 10:16), “Circumcise the foreskin of your heart,” which Onkelos renders: “your heart’s foolishness.” Thus, foolishness is the spoiling of the creation which comes about through wisdom.