Numbers 3:2-3

3:2 These are the names of the sons of Aaron: Nadab, the firstborn, and Abihu, Eleazar, and Ithamar. 3:3 These are the names of the sons of Aaron, the anointed priests, whom he consecrated to minister as priests.

Numbers 18:1

Responsibilities of the Priests

18:1 The Lord said to Aaron, “You and your sons and your tribe with you must bear the iniquity of the sanctuary, and you and your sons with you must bear the iniquity of your priesthood.

Numbers 18:7

18:7 But you and your sons with you are responsible for your priestly duties, for everything at the altar and within the curtain. And you must serve. I give you the priesthood as a gift for service; but the unauthorized person who approaches must be put to death.”

Exodus 6:16

6:16 Now these are the names of the sons of Levi, according to their records: Gershon, Kohath, and Merari. (The length of Levi’s life was 137 years.)

Exodus 6:20

6:20 Amram married his father’s sister Jochebed, and she bore him Aaron and Moses. (The length of Amram’s life was 137 years.)