Reference for Menachot 89:21
ת"ר (יחזקאל מו, ז) ואיפה לפר ואיפה לאיל יעשה מנחה ולכבשים כאשר תשיג ידו ושמן הין לאיפה א"ר שמעון וכי מדת פרים ואילים אחת היא
- R'Johanan said, This passage will be interpreted by Elijah in the future. Rabina said, It was necessary [to repeat this prohibition] for the priests, for I might have thought that since they are permitted [to eat] a bird-offering of which the head had been nipped off at the neck,<span class="x" onmousemove="('comment',' Bird-offerings were not slaughtered in the usual manner but their heads were nipped off at the neck, v. Lev. I, 15. After the application of the blood as prescribed, the priests were allowed to eat the flesh of the bird, although for profane purposes such nipping would render the bird nebelah.');"><sup>21</sup></span>