Deuteronomy 9:20

Israel could not even boast that its heads and representatives continued, faithful. Aaron had been already designated for the high priestly functions; but he fell away with the rest of the people. It was due therefore solely to the grace of God and the intercession of Moses that Aaron himself and his promised priesthood with him were not cut off; just as at a later time, when Aaron had actually to die for a new sin Israel owed it still to the same causes that Eleazar was substituted and the High Priesthood perpetuated (compare Deuteronomy 10:6; Numbers 20:24).