Мидраш к Шмот 40:32

4) (Vayikra 10:9) "when you come (to the tent of meeting"): I might think that this (stricture) applies only upon entering (the tent of meeting). Whence do I derive that it applies also upon leaving? From ("you and your sons) with you." Whence is it derived that (intending to sacrifice on) the altar (outside the tent of meeting) is comparable to (entering) the tent of meeting (in this respect)? It is, therefore, written ("you and your sons) with you." (in any area in which they are with you [i.e., distinct in being Cohanim]). And whence is it derived that he is liable only at the time of officiating (i.e., if he drank and then officiated)? From ("you and your sons) with you." Rebbi says: It is written here "when you come (to the tent of meeting") and elsewhere (Shemoth 28:43): "when they come to the tent of meeting." Just as there, leaving is equated with entering, and the altar with the tent of meeting, and there is liability only at the time of officiating, the same is true here.

5) He would perform five services: the morning tamid (daily burnt-offering) in golden vestments and the service of the day in white garments; his ram and the ram of the people, in white vestments. He then entered (the sanctuary) to take out the incense ladle and the coal pan, in white vestments, and he performed (the service of) the afternoon tamid in golden vestments. "And he shall bathe his flesh in water in a holy place and he shall put on his garments." This must be speaking of lustration of hands and feet. And whence is it derived that there are two lustrations of hands and feet for each immersion? From "and he shall take off … and he shall wash … and he shall wash and he shall put on" (connoting that lustration is required both for doffing and for donning.) R. Elazar b. R. Shimon said: This follows a fortiori, viz.: If in a place (the tent of meeting, all the days of the year) where immersion is not required, lustration of hands and feet is required (viz. Shemoth 40:32), then in a place where immersion is required (i.e., on Yom Kippur, for each change of clothing), how much more so is lustration of hands and feet required!