Temurah 9B

והומם וחללו על אחר, ונתכפר באשם אחר, וניתק לעולה ⁠— מהו שימיר בו?

and the original guilt offering became blemished, and he desacralized it by transferring its sanctity onto another animal, which was then lost, and the owner achieved atonement by bringing another, third, animal as a guilt offering, and then the second animal was found and was consigned to be sacrificed as a burnt offering, as is the case for any guilt offering whose owner has achieved atonement by means of another offering, what is the halakha as to whether he can effect substitution for the second animal? Since this animal’s sanctity stems from that of the original blemished animal, and he had already effected a substitute for that original animal, perhaps he cannot now substitute for the second animal, as this would constitute repeat substitution.

אמר אביי: מאי קא מיבעיא ליה? אי שני גופים וקדושה אחת ⁠— תיבעי ליה בלא מתכפר.

Abaye said: What is the dilemma he is raising? If his essential dilemma concerns the fact that there are two bodies, i.e., two different animals, then the dilemma would stand even if the original animal and the replacement were of one type of sanctity. If so, let the dilemma be raised even in a case where he did not achieve atonement by another guilt offering, and the second animal remained a guilt offering, rather than being consigned to be sacrificed as a burnt offering.

אי שתי קדושות, וגוף אחד ⁠— תיבעי ליה בלא הומם!

And if the dilemma is due to the fact that there are two types of sanctity, it would stand even if it was only one body. If so, let the dilemma be raised even where the animal did not become blemished but was simply lost and found after the owner atoned by means of another animal, and it was thereby consigned to be sacrificed as a burnt offering. Why did R' Avin present such a complex case?