Midrash su Levitico 21:23

6) "there is a blemish in him": to exclude (from disqualification) one whose blemish has left him. (The verse is needed, for without it we would say:) Does it not follow a fortiori (that this should disqualify him, viz.:) If a beast, which is unfit in the instance of "it and its son, etc.," is kasher in an instance of the blemish leaving it, then a man (a Cohein), who is kasher in the instance of he and his son, etc., should he not be kasher in an instance of the blemish leaving him?

10) (Vayikra 21:23) ("But to the veil he shall not come, and to the altar he shall not come near, for a blemish is in him; and he shall not profane My holy things, for I am the L–rd who sanctifies them.") If "to the veil" is written, why "to the altar"? And if "to the altar" is written, why "to the veil"? For if it were written "to the veil" and not "to the altar," I would say that he should be unfit for (entry to) the veil, which is within (the sanctuary), but not for the altar, which is not within. It must, therefore, be written "to the altar." And if it were written "to the altar," but not "to the veil," I would say that he is unfit for the altar, which is kasher for the (sacrificial) service, but not for the veil, which is not fit for the service, (but only for the sprinkling of the blood. It must, therefore, be written (both) "to the altar" and "to the veil."

11) I might think that he (a blemished Cohein) could not enter (between the hall and the altar) to do repair work; it is, therefore, written "But (to the veil he shall not come"), ("But" connoting limitation of exclusion. This is the mitzvah (for entry): Cohanim enter. If there are no Cohanim, Levites enter. If there are no (ritually) clean ones, unclean ones enter. If there are no unblemished ones, blemished ones enter. And whence is it derived that if he (a blemished Cohein) performed his (sacrificial) service, it is invalid? From "and he shall not profane My holy things." And whence is it derived that a blemished Cohein is liable to the death penalty (for such profanation)? R. Yehudah says: It is written here "profanation," and elsewhere (Vayikra 22:9) "profanation." Just as profanation there is punishable by death, here, too. And the sages say: A blemished Cohein is not subject to death, but to (violation of) an exhortation (Vayikra 21:17).