(ט) הַשְׁוָיַת הַקּוֹל כֵּיצַד. לֹא יַגְבִּיהַּ קוֹלוֹ בִּתְפִלָּתוֹ וְלֹא יִתְפַּלֵּל בְּלִבּוֹ אֶלָּא מְחַתֵּךְ הַדְּבָרִים בִּשְׂפָתָיו וּמַשְׁמִיעַ לְאָזְנָיו בְּלַחַשׁ. וְלֹא יַשְׁמִיעַ קוֹלוֹ אֶלָּא אִם כֵּן הָיָה חוֹלֶה אוֹ שֶׁאֵינוֹ יָכוֹל לְכַוֵּן אֶת לִבּוֹ עַד שֶׁיַּשְׁמִיעַ קוֹלוֹ, הֲרֵי זֶה מֻתָּר. וּבִלְבַד שֶׁלֹּא יְהֵא בְּצִבּוּר כְּדֵי שֶׁלֹּא תִּטָּרֵף דַּעְתָּן מִקּוֹלוֹ:
(9) Modulation of the voice: The voice should not be raised during the recital of the Amidah prayer nor should it be offered [silently] in thought alone. The words should be pronounced with the lips, but softly, and yet be audible to the speaker's ears. The worshiper should not permit their voice to be heard by others, unless they are sick, or are unable to concentrate their attention without reading aloud. One may not, however, do so at public worship, so that the congregants shall not be disturbed by their loud praying.
§ A baraita cited previously taught that the halakha against reciting a text out of order applies to the Amida prayer as well. The Gemara asks: From where do we derive this? As it is taught in a baraita: Shimon HaPakuli arranged the eighteen blessings of the Amida prayer before Rabban Gamliel in their fixed order in Yavne, which indicates that there is a specific order to these blessings that must not be changed. Rabbi Yoḥanan said, and some say that it was taught in a baraita: A hundred and twenty Elders, i.e., the Men of the Great Assembly, and among them several prophets, established the eighteen blessings of the Amida in their fixed order, which also shows that the order of these blessings may not be changed.
The Gemara returns to the baraita cited at the beginning of the discussion: Now, since the baraita teaches that a hundred and twenty Elders, including many prophets, established the Amida prayer in its fixed order, what is it that Shimon HaPakuli arranged in a much later period of time, as related by Rabbi Yoḥanan? The Gemara answers: Indeed, the blessings of the Amida prayer were originally arranged by the hundred and twenty members of the Great Assembly, but over the course of time the people forgot them, and Shimon HaPakuli then arranged them again.
In light of the previous mention of the blessing of the heretics, the Gemara explains how this blessing was instituted: The Sages taught: Shimon HaPakuli arranged the eighteen blessings, already extant during the period of the Great Assembly, before Rabban Gamliel, the Nasi of the Sanhedrin, in order in Yavne. Due to prevailing circumstances, there was a need to institute a new blessing directed against the heretics. Rabban Gamliel said to the Sages: Is there any person who knows to institute the blessing of the heretics, a blessing directed against the Sadducees? Shmuel HaKatan, who was one of the most pious men of that generation, stood and instituted it.