Reference for Bava Kamma 141:11

א"ל רב אשי התם לאו משום דלא מיחייב הוא אלא דקם ליה בדרבה מיניה

so also slaughter may be effected by another person. The School of R. Ishmael taught: [The term] 'or'<span class="x" onmousemove="('comment',' Ibid. ');">¹⁹</span> [inserted between 'slaughter' and 'selling' was meant] to include the case of an agent.<span class="x" onmousemove="('comment',' To make the principal liable to the fine. ');">²⁰</span>

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