12:2י״ב:ב׳
1 א

החדש הזה. הֶרְאָהוּ לְבָנָה בְּחִדּוּשָׁהּ וְאָמַר לוֹ כְּשֶׁהַיָּרֵחַ מִתְחַדֵּשׁ יִהְיֶה לְךָ רֹאשׁ חֹדֶשׁ (מכילתא). וְאֵין מִקְרָא יוֹצֵא מִידֵי פְשׁוּטוֹ, עַל חֹדֶשׁ נִיסָן אָמַר לוֹ, זֶה יִהְיֶה רֹאשׁ לְסֵדֶר מִנְיַן הֶחֳדָשִׁים, שֶׁיְּהֵא אִיָּר קָרוּי שֵׁנִי, סִיוָן שְׁלִישִׁי:

החדש הזה — He showed him the moon in the first stage of its renewal, and He said to him, “The time when the moon renews itself thus, shall be unto you the beginning of the month”. (The translation therefore is: “This stage of renewal (חדש) shall be the moment of beginning the months”; cf. Mekhilta d'Rabbi Yishmael 12:2:2). But no Scriptural verse can lose its literal meaning, and He really spoke this in reference to the month Nisan: this month shall be the beginning in the order of counting the months, so that Iyar shall be called the second, Sivan the third.

2 ב

הזה. נִתְקַשָּׁה מֹשֶׁה עַל מוֹלַד הַלְּבָנָה, בְּאֵיזוֹ שִׁעוּר תֵּרָאֶה וְתִהְיֶה רְאוּיָה לְקַדֵּשׁ, וְהֶרְאָה לוֹ בְּאֶצְבַּע אֶת הַלְּבָנָה בָּרָקִיעַ וְאָמַר לוֹ כָּזֶה רְאֵה וְקַדֵּשׁ (שם). וְכֵיצַד הֶרְאָהוּ? וַהֲלֹא לֹא הָיָה נִדְבָּר עִמּוֹ אֶלָּא בַּיּוֹם? שֶׁנֶּ' "וַיְהִי בְּיוֹם דִּבֶּר ה'" (שמות ו'), "בְּיוֹם צַוֹּתוֹ" (ויקרא ז'), "מִן הַיּוֹם אֲשֶׁר צִוָּה ה' וָהָלְאָה" (במדבר ט"ו)? אֶלָּא סָמוּךְ לִשְׁקִיעַת הַחַמָּה נֶאֶמְרָה לוֹ פָרָשָׁה זוֹ וְהֶרְאָהוּ עִם חֲשֵׁכָה:

הזה THIS [STAGE OF RENEWAL] — Moses was in perplexity regarding the Molad of (the exact moment when begins) the new moon — how much of it must be visible before it is proper to consecrate it as new moon: He therefore pointed it out to him in the sky with the finger and said to him, “Behold it like this, and consecrate it” (i. e., when you see the moon in a stage of renewal similar to this which you now behold you may proclaim that a new month has begun). But how could He point it out to him, for did He not conserve with him only by day, as it is said, (Exodus 6:28) “And it came to pass on the day when the Lord spake [unto Moses]”; (Leviticus 7:38) “On the day when he commanded”; (Numbers 15:23) “From the day that the Lord commanded and henceforward”? But the explanation is: This chapter was spoken to him close to sunset and He pointed it out to him at nightfall (more lit., near darkness) (Mekhilta d'Rabbi Yishmael 12:2:1).