משנה על ויקרא 16:12

Rabbi Joshua ben. Bathyra testified concerning the blood of carcasses that it was pure. Rabbi Shimon ben Bathyra testified concerning the ashes of purification, that if a defiled person had touched part of them he had defiled the whole of them. Rabbi Akiva added in regard to the fine flour, the incense, the frankincense, and the coals, that if a tevul yom had touched part of them he had made the whole of them unfit.