Numbers 3:11-13, 14-16, 44-48

GOD spoke to Moses: “I have taken the Levites from among the People of Israel as a stand-in for every Israelite mother’s firstborn son. The Levites belong to me. All the firstborn are mine—when I killed all the firstborn in Egypt, I consecrated for my own use every firstborn in Israel, whether human or animal. They belong to me. I am GOD.”

GOD spoke to Moses in the Wilderness of Sinai: “Count the Levites by their ancestral families and clans. Count every male a month old and older.” Moses counted them just as he was instructed by the mouth of GOD.

Again GOD spoke to Moses. He said, “Take the Levites in place of all the firstborn of Israel and the livestock of the Levites in place of their livestock. The Levites are mine, I am GOD. Redeem the 273 firstborn Israelites who exceed the number of Levites by collecting five shekels for each one, using the Sanctuary shekel (the shekel weighing twenty gerahs). Give that money to Aaron and his sons for the redemption of the excess number of Israelites.”