Talmud Bavli, Chullin
Chullin 2a
The Gemara elaborates on the Mishnah's opening ruling, discussing the qualifications of a shochet and the need for intent (kavanah) and proper technique. The sugya introduces the requirement that shechitah be performed with adequate knowledge and care, raising questions about supervision and oversight.
מַתְנִי׳ הַכֹּל שׁוֹחֲטִין וּשְׁחִיטָתָן כְּשֵׁרָה, חוּץ מֵחֵרֵשׁ שׁוֹטֶה וְקָטָן, שֶׁמָּא יְקַלְקְלוּ אֶת שְׁחִיטָתָן. וְכוּלָּן שֶׁשָּׁחֲטוּ וַאֲחֵרִים רוֹאִין אוֹתָן – שְׁחִיטָתָן כְּשֵׁרָה.
MISHNA: Everyone slaughters an animal, i.e., can perform halakhically valid slaughter, and their slaughter is valid, except for a deaf-mute, an imbecile, and a minor, lest they ruin their slaughter because they lack competence. And for all of them, when they slaughtered an animal and others see and supervise them, their slaughter is valid.
Why it matters — The Talmudic discussion of who may perform shechitah and under what conditions forms the basis for all later rulings on whether a shochet requires supervision or may be watched by others.