Shimon the Righteous was one of the last of the men of the great assembly. He used to say: the world stands upon three things: the Torah, the Temple service, and the practice of acts of piety.
ומצות עשה שהזמן גרמא נשים פטורות: ....גמר לה מתלמוד תורה מה תלמוד תורה נשים פטורות אף תפילין נשים פטורות
"and positive commandments that are time dependent, women are exempt."...Just like by [the commandment of] learning Torah women are exempt, so too by Tefillin women are exempt.
The obligation in this precept is that every person should daily, according to his ability, offer up supplication and prayer; first uttering praises of God, then, with humble supplication and petition ask for all that he needs, and finally offer praise and thanksgiving to the Eternal for the benefits already bestowed upon him in rich measure.
דַּבֵּ֤ר אֶֽל־אַהֲרֹן֙ וְאֶל־בָּנָ֣יו לֵאמֹ֔ר כֹּ֥ה תְבָרֲכ֖וּ אֶת־בְּנֵ֣י יִשְׂרָאֵ֑ל אָמ֖וֹר לָהֶֽם׃ (ס)
יְבָרֶכְךָ֥ ה' וְיִשְׁמְרֶֽךָ׃ (ס)
יָאֵ֨ר ה' ׀ פָּנָ֛יו אֵלֶ֖יךָ וִֽיחֻנֶּֽךָּ׃ (ס)
יִשָּׂ֨א ה' ׀ פָּנָיו֙ אֵלֶ֔יךָ וְיָשֵׂ֥ם לְךָ֖ שָׁלֽוֹם׃ (ס)
וְשָׂמ֥וּ אֶת־שְׁמִ֖י עַל־בְּנֵ֣י יִשְׂרָאֵ֑ל וַאֲנִ֖י אֲבָרֲכֵֽם׃ (פ)
Speak to Aaron and his sons: Thus shall you bless the people of Israel. Say to them:
The LORD bless you and protect you!
The LORD deal kindly and graciously with you!
The LORD bestow His favor upon you and grant you peace!
Thus they shall link My name with the people of Israel, and I will bless them.
וקורין עשרת הדברות שמע והיה אם שמוע ויאמר אמת ויציב ועבודה וברכת כהנים. אמר רב יהודה אמר שמואל אף בגבולין בקשו לקרות כן אלא שכבר בטלום מפני תרעומת המינין
In the Temple they read the Ten Commandments, Shema, VeHaya im Shamoa, VaYomer, Emet veYatziv, the Avoda, and the priestly benediction. Rav Yehuda in Shmuel's name: They sought to recite the Ten Commandments outside the Temple but it was already abolished due to the heretics.
(א) היה קורא בתורה, והגיע זמן המקרא: אם כיון לבו – יצא, ואם לאו – לא יצא.
(1) If one was reading [Shema] in the Torah, and it came time to recite [Shema]: If he directed his mind [and intended to fulfill his obligation to recite Shema as he read it], he has fulfilled his obligation. And if not, he has not fulfilled his obligation.
וּמִפְּנֵי זֶה כְּשֶׁהָיָה אֶחָד מֵהֶן מִתְפַּלֵּל תִּקְצַר לְשׁוֹנוֹ לִשְׁאל חֲפָצָיו אוֹ לְהַגִּיד שֶׁבַח הַקָּדוֹשׁ בָּרוּךְ הוּא בִּלְשׁוֹן הַקֹּדֶשׁ עַד שֶׁיֵּעָרְבוּ עִמָּהּ לְשׁוֹנוֹת אֲחֵרוֹת. וְכֵיוָן שֶׁרָאָה עֶזְרָא וּבֵית דִּינוֹ כָּךְ עָמְדוּ וְתִקְּנוּ לָהֶם שְׁמוֹנֶה עֶשְׂרֵה בְּרָכוֹת עַל הַסֵּדֶר. שָׁלֹשׁ רִאשׁוֹנוֹת שֶׁבַח לַה׳ וְשָׁלֹשׁ אַחֲרוֹנוֹת הוֹדָיָה. וְאֶמְצָעִיּוֹת יֵשׁ בָּהֶן שְׁאֵלַת כָּל הַדְּבָרִים שֶׁהֵן כְּמוֹ אָבוֹת לְכָל חֶפְצֵי אִישׁ וָאִישׁ וּלְצָרְכֵי הַצִּבּוּר כֻּלָּן, כְּדֵי שֶׁיִּהְיוּ עֲרוּכוֹת בְּפִי הַכּל וְיִלְמְדוּ אוֹתָן וְתִהְיֶה תְּפִלַּת אֵלּוּ הָעִלְּגִים תְּפִלָּה שְׁלֵמָה כִּתְפִלַּת בַּעֲלֵי הַלָּשׁוֹן הַצֶּחָה. וּמִפְּנֵי עִנְיָן זֶה תִּקְּנוּ כָּל הַבְּרָכוֹת וְהַתְּפִלּוֹת מְסֻדָּרוֹת בְּפִי כָּל יִשְׂרָאֵל כְּדֵי שֶׁיְּהֵא עִנְיַן כָּל בְּרָכָה עָרוּךְ בְּפִי הָעִלֵּג:
Consequently, when anyone of them prayed in Hebrew, he was unable adequately to express his needs or recount the praises of God, without mixing Hebrew with other languages. When Ezra and his Council realized this condition, they ordained the Eighteen Benedictions in their present order. The first three blessings consist of praises of God and the last three, of thanksgiving to Him. The intermediate benedictions are petitions for the things which may stand as categories of all the desires of the individual and the needs of the community. The object aimed at was that these prayers should be in an orderly form in everyone's mouth, that all should learn them, and thus the prayer of those who were not expert in speech would be as perfect as that of those who had command of a chaste style. For the same reason, they arranged [in a fixed form] all the blessings and prayers for all Jews so that the substance of every blessing should be familiar and current in the mouth of one who is not expert in speech.
וְכֵן תִּקְּנוּ שֶׁיְּהֵא מִנְיַן הַתְּפִלּוֹת כְּמִנְיַן הַקָּרְבָּנוֹת. שְׁתֵּי תְּפִלּוֹת בְּכָל יוֹם כְּנֶגֶד שְׁנֵי תְּמִידִין. וְכָל יוֹם שֶׁיֵּשׁ קָרְבַּן מוּסָף תִּקְּנוּ בּוֹ תְּפִלָּה שְׁלִישִׁית כְּנֶגֶד קָרְבַּן מוּסָף.
Thus, too, they ordained that the Services of Prayer should be equal in number to the Sacrifices—two services of prayer daily, corresponding to the two daily offerings. And for the day on which an additional offering was ordained, they instituted a third prayer, corresponding to the additional offering.