Meilah 11B

הרי תרומת הדשן, שנעשה מצותו, ויש בו מעילה!

But there is the instance of the removal of the ashes of offerings burned on the altar, whose mitzva has been performed and nevertheless it is still subject to misuse of consecrated property.

משום דהוה ליה תרומת הדשן ואיברי שעיר המשתלח שני כתובין הבאין כאחד, וכל שני כתובין הבאין כאחד ⁠– אין מלמדין.

The Talmud answers: The removal of the ashes cannot serve as a model for other halakhot whose mitzva has been performed, because the mitzva of the removal of the ashes and the limbs of the scapegoat of Yom Kippur after it was pushed off the cliff are both subject to the prohibition of misuse even after their mitzva has been performed. Consequently, they are two verses that come as one, i.e., they are two cases that share a unique halakha not found elsewhere. And there is a principle: Any two verses that come as one do not teach their common aspect to apply to other cases.

הניחא למאן דאמר איברי שעיר המשתלח ⁠– אין נהנין מהן, אלא למאן דאמר נהנין מהן, מאי איכא למימר?!

The Talmud objects: This works out well according to the one who said that one may not derive benefit from the limbs of the scapegoat, as this is a second verse indicating that an item can be subject to the halakha of misuse even after its mitzva has been performed. But according to the one who said that one may derive benefit from the limbs of the scapegoat, and they are not subject to the halakha of misuse, what can be said to explain why it is not possible to derive this halakha from the removal of the ashes? According to that opinion, this is not a case of two verses that come as one.