Reference for Chullin 7:13

כיוצא בו מצא בידו דקוריא של צפרין קוטע ראשו כו'

Perhaps it was only this one bird that he slaughtered properly? - R'Manasseh said, (Mnemonic: putting a knife on rams).<span class="x" onmousemove="('comment',' A mnemonic of the three laws taught by R. Manasseh in this Tractate. 'Putting' refers to the law dealt with here: 'where the Israelite put the basket . . ' 'Knife' v. infra 31a. 'Rams' v. infra 51a.');">⁵</span>

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