Chabad.org — English translation + Rashi
Torah Temimah points to Zevachim 28a.
E-Daf.com — Zevachim 28a
HebrewBooks / Shas PDF
English: One who slaughters the sacrifice intending to eat an olive-bulk of the tail’s hide outside — it is invalid; why? Rav Huna said: The hide of the alyah is not like meat.
Pigul/intent regarding alyah hide — intent to eat the alyah’s hide outside does not create the same invalidity as intent for the meat.
Intent to eat the alyah’s hide outside does not create the same invalidity as intent for the meat. Rav Huna explains that the hide of the alyah is not regarded as flesh; therefore an intention directed at that hide does not trigger the full pigul consequence that would apply to an intention directed at the edible meat of the offering. The distinction protects the validity of the sacrifice when the improper intent concerns only the hide.