Reference for Eruvin 124:12

א"ל ר' יעקב בר אבא לאביי כגון מגלת תענית דכתיבא ומנחא מהו לאורויי באתרי דרביה א"ל הכי א"ר יוסף אפי' ביעתא בכותחא בעו מיניה מרב חסדא כל שני דרב הונא ולא אורי

- Thus, the other replied, said R'Joseph: Even on the question of the permissibility of eating an egg<span class="x" onmousemove="('comment',' A perfectly developed egg found in a slaughtered fowl (so Tosaf. s.v. a.l.) . The question whether a properly laid egg may be eaten with milk (cf. following n.) could, of course, never arise (v. however, Rashi) .');">²⁶</span> with kutha,<span class="x" onmousemove="('comment',' A preserve containing milk.');">²⁷</span> which I<span class="x" onmousemove="('comment',' So MS.M. and Bah. Cur. edd. 'they'.');">²⁸</span> have been asking him<span class="x" onmousemove="('comment',' To test his loyalty to his Master. cr');">²⁹</span>

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