‘On and Off His Forehead’
Among the eight garments worn by the kohen gadol was the tzitz ha’zahav, the golden plate bearing Hashem’s name. The pasuk states, “It will be on the brow of Aharon. And Aharon will bear the sin of the [impure] korbanos that Bnei Yisrael will offer” (Shemos 28:38). Our Sages derive from this verse that the tzitz atones for impure korbanos that are offered in the beis hamikdash (see above, 16b).
The Tannaim debate whether the tzitz atones only for those korbanos offered while the kohen gadol wears it, or even for those offered when he is not wearing it. The Rambam (Bias Mikdash 4:8) rules according to Rabbi Yehuda that the tzitz only atones so long as it is being worn.
Two points remain to be clarified. First, does the kohen gadol need to wear all eight garments in order for the tzitz to be effective, or does it atone even if he wears it without the other garments? Second, need the kohen gadol be inside the beis hamikdash for the tzitz to be effective, or is it effective even outside the beis hamikdash (assuming, for a moment, that he can wear it there)? As we shall see, the answers to both these questions are intertwined.
The Belt Is Made Of Shaatnez
The sefer VeShav HaKohen (beginning of Maseches Erchin) cites from the Talmud Yerushalmi (Chagiga 4:4) that the kohen gadol must wear all eight garments in order for the tzitz to atone. The Dvar Avraham (2:22) develops from this Yerushalmi an important insight into the Rambam’s understanding of the kohen gadol’s garments. The Rambam (Kilayim 10:32) writes: “Kohanim who wear their priestly garments while not serving, even if they are in the beis hamikdash, must be flogged for wearing their belt, which is made of shaatnez. They are only permitted to wear this belt while they serve.”
The Torah tells us that the belt must be made of wool and linen. While the kohanim serve, the mitzvah to wear this belt takes precedence over the prohibition against shaatnez. When they are not serving, there is no mitzvah to wear the belt, and they thus transgress the prohibition of shaatnez by wearing it.
The Raavad and other Rishonim (see Kesef Mishnah) dispute the Rambam’s ruling and insist that as long as the kohanim are inside the beis hamikdash, they may wear their belts, even when they are not serving. A proof against the Rambam’s position is a Tosefta which says that a kohen gadol can wear his special garments as long as he is in the beis hamikdash (whether serving or not), despite the fact that the ephod and choshen were made of shaatnez. Apparently, then, as long as a kohen (gadol) is in the beis hamikdash, he may wear his shaatnez garment(s), even if he is not serving – contra the Rambam.
The Dvar Avraham, however, explains, based on the Yerushalmi, that even when a kohen gadol doesn’t serve, he still needs to wear his eight garments so that the tzitz can atone for impure korbanos. In other words, the kohen gadol has a reason for wearing shaatnez when not serving which regular kohanim do not have (and thus, the Rambam’s ruling does not contradict that of the Tosefta).
Beyond The Pale
Why, however, does the Tosefta rule that a kohen gadol can only wear his garments in the beis hamikdash? Since we want the tzitz to be effective, he should be allowed to wear them anywhere. We are therefore forced to conclude that the tzitz is ineffective outside the beis hamikdash. If it were effective, the Tosefta presumably would’ve ruled differently.
We have thus answered both our questions. The kohen gadol must wear all eight garments and must be in the beis hamikdash for the tzitz to be effective.