Reference for Bekhorot 51:39

אינו נראה עם הגיזה מותר דמעיקרא תליש

But if the Mishnah gives the opinion of the Rabbis, then in both instances they indeed forbid<span class="x" onmousemove="('comment',' For that which is attached to the dead animal requires burial according to all, and of that which is detached the Rabbis prohibit the use, even to place it in the window.');">¹⁷</span>

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