Reference for Zevachim 184:15

בעי רבי אבין נשפך על הרצפה ואספה מהו

- Come and hear: If it [the bird] struggled, entered within<span class="x" onmousemove="('comment',' Into the hekal.');">¹⁹</span> and then returned,<span class="x" onmousemove="('comment',' I.e., its head was nipped near the hekal, and in its death struggles it entered therein.');">²⁰</span>

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