ראש השנה ג׳Rosh Hashanah 3

Mishnah 1א׳

רָאוּהוּ בֵית דִּין וְכָל יִשְׂרָאֵל, נֶחְקְרוּ הָעֵדִים, וְלֹא הִסְפִּיקוּ לוֹמַר מְקֻדָּשׁ, עַד שֶׁחֲשֵׁכָה, הֲרֵי זֶה מְעֻבָּר. רָאוּהוּ בֵית דִּין בִּלְבַד, יַעַמְדוּ שְׁנַיִם וְיָעִידוּ בִפְנֵיהֶם, וְיֹאמְרוּ מְקֻדָּשׁ מְקֻדָּשׁ. רָאוּהוּ שְׁלשָׁה וְהֵן בֵּית דִּין, יַעַמְדוּ הַשְּׁנַיִם וְיוֹשִׁיבוּ מֵחַבְרֵיהֶם אֵצֶל הַיָּחִיד וְיָעִידוּ בִפְנֵיהֶם, וְיֹאמְרוּ מְקֻדָּשׁ מְקֻדָּשׁ, שֶׁאֵין הַיָּחִיד נֶאֱמָן עַל יְדֵי עַצְמוֹ:

If the Beth Din and all Israel saw the new moon, 1 or if the examination of the witnesses had already taken place, but it had become dark before the word "Mekudash [It is sanctified]," was pronounced, the month will be intercalary. When the Beth Din alone saw it, two of its members must stand up before the others as witnesses, who shall then say, "It is sanctified, it is sanctified." When only three forming a Beth Din have seen it, two of them must stand up as witnesses, and conjoin some of their learned associates with the single one, and then give their evidence before these, who are to say, "It is sanctified, it is sanctified," because a single member of a Beth Din has not this faculty by himself alone.

Mishnah 2ב׳

כָּל הַשּׁוֹפָרוֹת כְּשֵׁרִין חוּץ מִשֶּׁל פָּרָה, מִפְּנֵי שֶׁהוּא קֶרֶן. אָמַר רַבִּי יוֹסֵי, וַהֲלֹא כָל הַשּׁוֹפָרוֹת נִקְרְאוּ קֶרֶן, שֶׁנֶּאֱמַר (יהושע ו), בִּמְשֹׁךְ בְּקֶרֶן הַיּוֹבֵל:

All shofars are acceptable, except that of a cow because it is a horn (“keren”). Rabbi Yosi said: But all shofars are called “keren”, as it states, “upon a long blast from the ram’s horn ('keren')” (Josh. 6:5).