Reference for Chullin 205:4

בשלמא לר' יוחנן ניחא אלא לר' שמעון בן לקיש קשיא

In the case of two animals<span class="x" onmousemove="('comment',' I.e., he ate a limb severed from a living animal and also flesh taken from another animal which was trefah.');">²</span>

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