Reference for Zevachim 44:12
אמר עולא תקע להו ר"ל לדרומאי וכי איזה כח מרובה כח מכפרין או כח מתכפרין הוי אומר כח מתכפרין
IS DISQUALIFIED. The Elders of the South said: They learnt this only of [a priest] unclean through a reptile, but [as for] one unclean through a corpse, since [the headplate] propitiates in the case of a public sacrifice, it propitiates in the case of a private sacrifice.<span class="x" onmousemove="('comment',' V. Ex. XXVIII, 36-38: And thou shalt make a pale of pure gold . . and it shall be upon Aaron's forehead, and Aaron shall bear the iniquity committed in the holy things . . and it shall always be upon his forehead, that they may be accepted before the Lord. According to the Rabbis, this means that in virtue of the headplate a public sacrifice is 'accepted', i.e., valid, even if the whole congregation or all the officiating priests are unclean, and indeed must be offered at the very outset in such conditions, as the public sacrifice may not be postponed. This is technically called propitiating (making acceptable) . The matter is further explained in the text.');"><sup>10</sup></span>