תְּפִלַּת הַשַּׁחַר, עַד חֲצוֹת. רַבִּי יְהוּדָה אוֹמֵר, עַד אַרְבַּע שָׁעוֹת. תְּפִלַּת הַמִּנְחָה עַד הָעֶרֶב. רַבִּי יְהוּדָה אוֹמֵר, עַד פְּלַג הַמִּנְחָה. תְּפִלַּת הָעֶרֶב אֵין לָהּ קֶבַע. וְשֶׁל מוּסָפִין כָּל הַיּוֹם. רַבִּי יְהוּדָה אוֹמֵר, עַד שֶׁבַע שָׁעוֹת:
רַבִּי נְחוּנְיָא בֶּן הַקָּנָה הָיָה מִתְפַּלֵּל בִּכְנִיסָתוֹ לְבֵית הַמִּדְרָשׁ וּבִיצִיאָתוֹ תְּפִלָּה קְצָרָה. אָמְרוּ לוֹ, מַה מָּקוֹם לִתְפִלָּה זוֹ. אָמַר לָהֶם, בִּכְנִיסָתִי אֲנִי מִתְפַּלֵּל שֶׁלֹּא תֶאֱרַע תַּקָלָה עַל יָדִי, וּבִיצִיאָתִי אֲנִי נוֹתֵן הוֹדָיָה עַל חֶלְקִי:
הָעוֹבֵר לִפְנֵי הַתֵּיבָה, לֹא יַעֲנֶה אַחַר הַכֹּהֲנִים אָמֵן, מִפְּנֵי הַטֵּרוּף. וְאִם אֵין שָׁם כֹּהֵן אֶלָּא הוּא, לֹא יִשָּׂא אֶת כַּפָּיו. וְאִם הַבְטָחָתוֹ שֶׁהוּא נוֹשֵׂא אֶת כַּפָּיו וְחוֹזֵר לִתְפִלָּתוֹ, רַשַּׁאי:
בָּרִאשׁוֹנָה הָיוּ מְקַבְּלִין עֵדוּת הַחֹדֶשׁ כָּל הַיּוֹם. פַּעַם אַחַת נִשְׁתַּהוּ הָעֵדִים מִלָּבֹא, וְנִתְקַלְקְלוּ הַלְוִיִּם בַּשִּׁיר. הִתְקִינוּ שֶׁלֹּא יְהוּ מְקַבְּלִין אֶלָּא עַד הַמִּנְחָה. וְאִם בָּאוּ עֵדִים מִן הַמִּנְחָה וּלְמַעְלָה, נוֹהֲגִין אוֹתוֹ הַיּוֹם קֹדֶשׁ וּלְמָחָר קֹדֶשׁ. מִשֶּׁחָרַב בֵּית הַמִּקְדָּשׁ הִתְקִין רַבָּן יוֹחָנָן בֶּן זַכַּאי, שֶׁיְּהוּ מְקַבְּלִין עֵדוּת הַחֹדֶשׁ כָּל הַיּוֹם. אָמַר רַבִּי יְהוֹשֻׁעַ בֶּן קָרְחָה, וְעוֹד זֹאת הִתְקִין רַבָּן יוֹחָנָן בֶּן זַכַּאי, שֶׁאֲפִלּוּ רֹאשׁ בֵּית דִּין בְּכָל מָקוֹם, שֶׁלֹּא יְהוּ הָעֵדִים הוֹלְכִין אֶלָּא לִמְקוֹם הַוָּעַד:
שׁוֹפָר שֶׁל רֹאשׁ הַשָּׁנָה, אֵין מַעֲבִירִין עָלָיו אֶת הַתְּחוּם, וְאֵין מְפַקְּחִין עָלָיו אֶת הַגַּל, לֹא עוֹלִין בְּאִילָן, וְלֹא רוֹכְבִין עַל גַּבֵּי בְהֵמָה, וְלֹא שָׁטִין עַל פְּנֵי הַמַּיִם, וְאֵין חוֹתְכִין אוֹתוֹ בֵּין בְּדָבָר שֶׁהוּא מִשּׁוּם שְׁבוּת, וּבֵין בְּדָבָר שֶׁהוּא מִשּׁוּם לֹא תַעֲשֶׂה. אֲבָל אִם רָצָה לִתֵּן לְתוֹכוֹ מַיִם אוֹ יַיִן, יִתֵּן. אֵין מְעַכְּבִין אֶת הַתִּינוֹקוֹת מִלִּתְקוֹעַ, אֲבָל מִתְעַסְּקִין עִמָּהֶן עַד שֶׁיִּלְמְדוּ. וְהַמִּתְעַסֵּק, לֹא יָצָא, וְהַשּׁוֹמֵעַ מִן הַמִּתְעַסֵּק, לֹא יָצָא:
משנה תורה Mishna Torah c.1176 - c.1178 CE רמב׳ם
The Mishneh Torah (“Repetition of the Torah”), also referred to as Yad HaChazakah (“The Strong Hand”), is a monumental legal code and one of the most organized, comprehensive, and influential works of Jewish law. Written over a period of ten years, the work systematically categorizes and clearly explains all aspects of Jewish observance, including those applicable only in Temple times.
The number of prayers is not prescribed in the Torah, nor does it prescribe a specific formula for prayer. Also, according to Torah law, there are no fixed times for prayers.
Rather, this commandment obligates each person to offer supplication and prayer every day and utter praises of the Holy One, blessed be He; then petition for all his needs with requests and supplications; and finally, give praise and thanks to God for the goodness that He has bestowed upon him; each one according to his own ability.
Similarly, the number of prayers was dependent on each person's ability. Some would pray once daily; others, several times.
Everyone would pray facing the Holy Temple, wherever he might be. This was the ongoing practice from [the time of] Moshe Rabbenu until Ezra.
The speech of each and every one was a concoction of many tongues. No one was able to express himself coherently in any one language, but rather in a mixture [of languages], as [Nehemiah 13:24] states: "And their children spoke half in Ashdodit and did not know how to speak the Jewish language. Rather, [they would speak] according to the language of various other peoples."
Consequently, when someone would pray, he would be limited in his ability to request his needs or to praise the Holy One, blessed be He, in Hebrew, unless other languages were mixed in with it. When Ezra and his court saw this, they established eighteen blessings in sequence.
The first three [blessings] are praises of God and the last three are thanksgiving. The intermediate [blessings] contain requests for all those things that serve as general categories for the desires of each and every person and the needs of the whole community.
Thus, the prayers could be set in the mouths of everyone. They could learn them quickly and the prayers of those unable to express themselves would be as complete as the prayers of the most eloquent. It was because of this matter that they established all the blessings and prayers so that they would be ordered in the mouths of all Israel, so that each blessing would be set in the mouth of each person unable to express himself.
The prayer that corresponds to the daily morning sacrifice is called the Shacharit Prayer. The prayer that corresponds to the daily sacrifice offered in the afternoon is called the Minchah Prayer and the prayer corresponding to the additional offerings is called the Musaf Prayer.
The Evening Prayer is not obligatory, as are the Morning and Minchah Prayers. Nevertheless, the Jewish people, in all the places that they have settled, are accustomed to recite the Evening Prayer and have accepted it upon themselves as an obligatory prayer.
This is called the Ne'ilah prayer, as if to say that the gates of Heaven are closed behind the sun, which becomes hidden, since it is recited only close to [the time of] sunset.
Any prayer that one adds is considered as a freewill offering. Therefore, one must add a new idea consistent with that blessing in each of the middle blessings. [However], making an addition of a new concept even in only one blessing is sufficient in order to make known that this is a voluntary prayer and not obligatory.
In the first three [blessings] and the last three [blessings], one must never add, detract or change anything at all.