The Number and Duties of the Levites

31 This is the account of the family of Aaron and Moses at the time the Lord spoke to Moses at Mount Sinai. 2 The names of the sons of Aaron were Nadab the firstborn and Abihu, Eleazar and Ithamar. 3 Those were the names of Aaron's sons, the anointed priests, who were ordained to serve as priests. 4 Nadab and Abihu, however, died before the Lord when they made an offering with unauthorized fire before him in the Desert of Sinai. They had no sons, so Eleazar and Ithamar served as priests during the lifetime of their father Aaron. 5 The Lord said to Moses, 6 "Bring the tribe of Levi and present them to Aaron the priest to assist him. 7 They are to perform duties for him and for the whole community at the tent of meeting by doing the work of the tabernacle. 8 They are to take care of all the furnishings of the tent of meeting, fulfilling the obligations of the Israelites by doing the work of the tabernacle. 9 Give the Levites to Aaron and his sons; they are the Israelites who are to be given wholly to him.[1] 10 Appoint Aaron and his sons to serve as priests; anyone else who approaches the sanctuary is to be put to death." 11 The Lord also said to Moses, 12 "I have taken the Levites from among the Israelites in place of the first male offspring of every Israelite woman. The Levites are mine, 13 for all the firstborn are mine. When I struck down all the firstborn in Egypt, I set apart for myself every firstborn in Israel, whether human or animal. They are to be mine. I am the Lord."

Matthew Henry's Commentary on Numbers 3:1-13

Commentary on Numbers 3:1-13

(Read Numbers 3:1-13)

There was much work belonging to the priests' office, and there were now only Aaron and his two sons to do it; God appoints the Levites to attend them. Those whom God finds work for, he will find help for. The Levites were taken instead of the first-born. When He that made us, saves us, as the first-born of Israel were saved, we are laid under further obligations to serve him faithfully. God's right to us by redemption, confirms the right he has to us by creation.