Reference for Chullin 82:36

פסח בר נידב ונידר הוא

R'Johanan said: The Mishnah refers only to the case where he [the slaughterer] was not obliged to bring a sin-offering, but where he was obliged to bring a sin-offering it might be said that he is slaughtering the animal as his sin-offering.<span class="x" onmousemove="('comment',' And the slaughtering would be invalid.');">¹⁴</span>

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