In Exodus 32:26–29 we read that after the incident at Mount Sinai and the making of the golden calf, Moses forced the people to make a choice, calling those who were on the Lord’s side to come to him. Only the Levites came. The Levites were then called to execute God’s wrath upon those who refused to side with the Lord, which they did. The result was that they were ordained to the service of the Lord. This covenant was confirmed in Numbers 25:11–13 when Phinehas showed great zeal for the holiness of the Lord by executing the evil Israelite who had taken a Midianite woman into his tent. God’s covenant with Levi was that his descendants would serve as priests forever.
4 So shall you know that I have sent this command to you, that my covenant with Levi may stand, says the LORD of hosts.