Numbers 3:12

3:12 “Look, I myself have taken the Levites from among the Israelites instead of every firstborn who opens the womb among the Israelites. So the Levites belong to me,

Numbers 3:43

3:43 And all the firstborn males, by the number of the names from a month old and upward, totaled 22,273.

Numbers 3:45

3:45 “Take the Levites instead of all the firstborn males among the Israelites, and the livestock of the Levites instead of their livestock. And the Levites will be mine. I am the Lord.

Numbers 3:50

3:50 From the firstborn males of the Israelites he collected the money, 1,365 shekels, according to the sanctuary shekel.

Numbers 33:4

33:4 Now the Egyptians were burying all their firstborn, whom the Lord had killed among them; the Lord also executed judgments on their gods.