Commento su Hullin 5:5
יוֹם אֶחָד הָאָמוּר בְּאוֹתוֹ וְאֶת בְּנוֹ, הַיּוֹם הוֹלֵךְ אַחַר הַלָּיְלָה. אֶת זוֹ דָרַשׁ שִׁמְעוֹן בֶּן זוֹמָא. נֶאֱמַר בְּמַעֲשֵׂה בְרֵאשִׁית (בראשית א), יוֹם אֶחָד, וְנֶאֱמַר בְּאוֹתוֹ וְאֶת בְּנוֹ (ויקרא כב), יוֹם אֶחָד. מַה יּוֹם אֶחָד הָאָמוּר בְּמַעֲשֵׂה בְרֵאשִׁית הַיּוֹם הוֹלֵךְ אַחַר הַלַּיְלָה, אַף יוֹם אֶחָד הָאָמוּר בְּאוֹתוֹ וְאֶת בְּנוֹ, הַיוֹם הוֹלֵךְ אַחַר הַלָּיְלָה:
L'espressione della legge, "Un giorno", quando si tratta del divieto di macellare un animale e i suoi piccoli in un [e lo stesso] giorno, deve essere intesa, che il giorno e la notte che lo hanno preceduto devono essere calcolati insieme [come formando un giorno]. Perché così fu esposto da R. Shimon ben Zomah, "Il termine (Genesi 1: 5, Levitico 22:28)" un giorno "è usato nella storia della Creazione e anche nel divieto di macellare un animale e i suoi giovani, per insegnaci che, proprio come nella Creazione, il giorno seguiva la notte, quindi anche in questo caso deve essere compreso ".
Bartenura on Mishnah Chullin
English Explanation of Mishnah Chullin
This was how Rabbi Shimon ben Zoma expounded (: it says “one day” (Genesis 1:5) in connection with the creation and it also says “one day” (Leviticus 22:28) in connection with “it and its young” Just as the “one day” mentioned in connection with the creation means the day and the night preceding it, so too the “one day” mentioned in connection with “it and its young” means the day and the night preceding it.
This mishnah, which I shall explain here and not below, teaches that when we reckon the day on which an animal was slaughtered, the night goes with the day that follows it. Thus if he slaughtered one animal at night and then the following day he slaughtered its mother or offspring, he has violated the law of “it and its young.” But if he slaughters an animal during the day and then the following night he slaughters its mother or young, he has not violated the law.
The basis for this law are the verses from Genesis 1 that state, “and it was evening and it was morning, the first day,” and so on for each day. These verses imply, to the rabbis, that the day begins with the preceding night. And since the words “one day” are used in the context of creation and in the context of the law concerning “it and its young,” the day is reckoned in the same way for each.