Rabbi Tanḥum ben Rabbi Ḥanilai said: Moses gave us in writing two portions in the Torah and they are ritually pure.13They are about ritual purity. Through whom were they given? Through the tribe of Levi, in whose regard it is written: “Silver purified in the furnace of the earth” (Psalms 12:7), and it is written: “He will sit refining and purifying silver, and he will purify the sons of Levi, and purge them” (Malachi 3:3). Which are they? They are the red heifer and the portion of the corpse.14This is a reference to Leviticus 21:1–4, where priests are prohibited from becoming ritually impure from a corpse.