Deuteronomy 14:6

מפרסת means split, as the Targum has it. פרסה - plante in O. F. (English = hoof). ושסעת AND HATH CLOVEN [HOOFS] — i.e. hoofs divided into two nails, for there are animals with hoofs split but not entirely divided into two nails (cf. Rashi on Leviticus 9:3), and such are unclean. בבהמה [AND EVERY BEAST THAT PARTETH THE HOOF …] AMONG THE BEASTS [YE MAY EAT] — if one takes בבהמה to signify “within the animal”, it suggests: that which is found in the beast you may eat. From here, therefore, they (the Rabbis) derived the law that a שליל (a fully developed embryo) becomes permitted to be eaten through the slaughter of its mother without requiring ritual slaughtering itself (Chullin 69a; Chullin 74a).

וְכׇל־בְּהֵמָ֞ה מַפְרֶ֣סֶת פַּרְסָ֗ה וְשֹׁסַ֤עַת שֶׁ֙סַע֙ שְׁתֵּ֣י פְרָס֔וֹת מַעֲלַ֥ת גֵּרָ֖ה בַּבְּהֵמָ֑ה אֹתָ֖הּ תֹּאכֵֽלוּ׃

And every beast that parts the hoof, forming thereby two entirely cloven hoofs, and chews the cud among the beasts, that may you eat.