Derasha on Bo 12:2 — Torah Temimah note 8

Parashas Bo · Shemos 12:2 · TT note 8

The Complete Passuk

הַחֹ֧דֶשׁ הַזֶּ֛ה לָכֶ֖ם רֹ֣אשׁ חֳדָשִׁ֑ים רִאשׁ֥וֹן הוּא֙ לָכֶ֔ם לְחׇדְשֵׁ֖י הַשָּׁנָֽה׃

Torah Temimah on Shemos 12:2, note 8 (on רֹאשׁ חֳדָשִׁים) points to Yerushalmi Rosh Hashanah 1:1.

Core Text — Yerushalmi Rosh Hashanah 1:1 (via Torah Temimah)

רֹאשׁ לַחֳדָשִׁים וְלֹא רֹאשׁ לַשָּׁנִים, אֶלָּא שָׁנִים מִתִּשְׁרֵי מָנֵינַן.

English: [Nisan is] the head of the months and not the head of the years; rather, years are counted from Tishrei.

Distinction: Nisan heads the monthly count; the year-count for other purposes begins in Tishrei.

This passuk establishes Nisan as first of the months, while years (for many reckonings) are still counted from Tishrei.