Reference for Keritot 34:12

במאי קא מיפלגי

<big><b>GEMARA: </b></big>It was stated: Rab Assi said, [The first case of the Mishnah] refers to one piece about which there was a doubt whether it was heleb or permissible fat; Hiyya B'Rab said: It refers to one of two pieces.<span class="x" onmousemove="('comment',' I.e., he ate one of two pieces that lay before him, one of which was certainly permissible and the other certainly heleb, which were mixed up one with the other.');">⁸</span>

Jastrow