Bilangan 8:19

8:19 I have given the Levites as a gift to Aaron and his sons from among the Israelites, to do the work for the Israelites in the tent of meeting, and to make atonement for the Israelites, so there will be no plague among the Israelites when the Israelites come near the sanctuary.” ¹ 

Bilangan 16:46

16:46 Then Moses said to Aaron, “Take the censer, put burning coals from the altar in it, place incense on it, and go quickly into the assembly and make atonement for them, for wrath has gone out from the Lord – the plague has begun!”

Bilangan 31:30

31:30 From the Israelites’ half-share you are to take one portion out of fifty of the people, the cattle, the donkeys, and the sheep – from every kind of animal – and you are to give them to the Levites, who are responsible for the care of the Lord’s tabernacle.”

Bilangan 31:47

31:47 From the Israelites’ share Moses took one of every fifty people and animals and gave them to the Levites who were responsible for the care of the Lord’s tabernacle, just as the Lord commanded Moses.

[8:19]  ¹ sn The firstborn were those that were essentially redeemed from death in Egypt when the blood was put on the doors. So in the very real sense they belonged to God (Exod 13:2,12). The firstborn was one who stood in special relationship to the father, being the successive offspring. Here, the Levites would stand in for the firstborn in that special role and special relationship. God also made it clear that the nation of Israel was his firstborn son (Exod 4:22-23), and so they stood in that relationship before all the nations. The tribe of Reuben was to have been the firstborn tribe, but in view of the presumptuous attempt to take over the leadership through pagan methods (Gen 35:22; 49:3-4), was passed over. The tribes of Levi and Simeon were also put down for their ancestors’ activities, but sanctuary service was still given to Levi.