Maleakhi 2:4

2:4 Then you will know that I sent this commandment to you so that my covenant ¹  may continue to be with Levi,” says the Lord who rules over all.

[2:4]  ¹ sn My covenant refers to the priestly covenant through Aaron and his grandson Phinehas (see Exod 6:16-20; Num 25:10-13; Jer 33:21-22). The point here is to contrast the priestly ideal with the disgraceful manner in which it was being carried out in postexilic times.