Moses Divides the Blood of the Covenant at Sinai

(Exodus 24:6-8) "And Moses took the blood and dashed it upon the people." And it is a received tradition that there is no sprinkling without immersion. From here we learn that our forefathers were circumcised and immersed. And a convert who was circumcised but did not immerse is not a convert. "And Moses took half the blood." From where did Moses know which was half the blood? Rabbi Judah son of Rabbi Ila'i says: the blood divided of its own accord. Rabbi Nathan says: a miracle was performed with it, half of it turned black and half of it turned red. Rabbi Isaac said: a heavenly voice went forth from Mount Horeb and said to Moses, "Up to here is half the blood." Bar Kappara said: an angel came down from heaven in the likeness of Moses and divided it. Rabbi Ishmael taught: Moses was expert in the laws of blood, and he divided it. "And he put it in basins." It is written "in the basins" [two basins], neither one larger than the other. He [the people] said to him: what shall be done with your portion? He said to them: dash it upon the altar, as it is said, "And half the blood he dashed upon the altar." He swore to them and they swore to him, as it is said, "that you should enter into the covenant of the LORD and into His oath" (Deuteronomy 29:11), and he swore to them, "And I swore to you, and entered into a covenant with you" (and so on).