The Shulchan Aruch · Yoreh De'ah
יורה דעה כ״זYoreh De'ah 27
Siman 27 of 402 in Yoreh De'ah — 1 se'if
הלכות שחיטהRitual Slaughter· siman 27
Se’if 1א׳
חָתַךְ מִבְּהֵמָה לְאַחַר שֶׁנִּשְׁחֲטָה כָּרָאוּי וְעוֹדֵּנָהּ מְפַרְכֶּסֶת, אָסוּר לֶאֱכֹל מִמֶּנָּהּ עַד שֶׁתָּמוּת הַבְּהֵמָה.
If he cut from an animal after it had been slaughtered properly and it is still convulsing, it is forbidden to eat of it until the animal dies.
Shulchan Aruch, Yoreh De'ah — Torat Emet 357 edition, via Sefaria — public domain
English rendered from the Hebrew for this app — The Gematria's own rendering program. A rendering of the words, not a ruling; practical halacha is learned with a rav