לֹ֣א תֹאכְל֣וּ כָל־נְ֠בֵלָה לַגֵּ֨ר אֲשֶׁר־בִּשְׁעָרֶ֜יךָ תִּתְּנֶ֣נָּה וַאֲכָלָ֗הּ א֤וֹ מָכֹר֙ לְנָכְרִ֔י כִּ֣י עַ֤ם קָדוֹשׁ֙ אַתָּ֔ה לַיהוָ֖ה אֱלֹהֶ֑יךָ לֹֽא־תְבַשֵּׁ֥ל גְּדִ֖י בַּחֲלֵ֥ב אִמּֽוֹ׃ (פ)
Huwag kayong kakain ng anumang hayop na namatay nang hindi kinatay; maaari mo itong ibigay sa dayuhang naninirahan sa loob ng iyong mga bayan upang kanyang kainin, o ipagbili ito sa banyaga; sapagkat ikaw ay isang banal na bayan para sa Walang-Hanggan na iyong Diyos. Huwag mong lulutuin ang batang kambing sa gatas ng kanyang ina.
Tze'enah Ure'enah
“You shall no boil a kid in its mother’s milk” [14:21]. You should not boil meat with milk. The Torah wrote three times that you should not boil meat with milk. This shows us the meaning of not boiling meat with milk. Even when you do not want to eat it, you would boil it for a gentile and the people were not warned about this. They boil meat with milk for gentiles in their homes. The second thing is, one should not eat meat with milk. The third is, one should have no benefit when one boils meat with milk, if one wanted to sell it to a gentile. He should not even give it to his dog.17Bahya, Deuteronomy, 14:21.
Rashi
לגר אשר בשעריך [YE SHALL NOT EAT ANY CARRION: THOU SHALT GIVE IT] UNTO THE STRANGER THAT IS IN THY GATES — i.e. unto a stranger that is a sojourner (גר תושב) — one who has undertaken not to worship idols (i.e. one who has been converted to the fundamental tenet of Judaism) but who eats carrion (does not obey the other teachings of the Torah) (Sifrei Devarim 104:2; cf. Rashi on Leviticus 25:35).
Ibn Ezra
you must not eat anything that died by itself whether a bird, or a beast.