And ye shall know that I have {f} sent this commandment unto you, that my covenant might be with Levi, saith the LORD of hosts.

(f) The Priests objected against the Prophet that he could not remove them without speaking against the priesthood, and the office established by God by promise. But he shows that the office is nothing slandered, when these villains and dung are called by their own names.

Wesley's Notes

2:4 My covenant - If you will not confirm, and keep Levi's covenant among you, I will make it firm on my part, by punishing the violators of it.

Jamieson-Fausset-Brown Bible Commentary

4. ye shall know-by bitter experience of consequences, that it was with this design I admonished you, in order "that My covenant with Levi might be" maintained; that is, that it was for your own good (which would be ensured by your maintaining the Levitical command) I admonished you, that ye should return to your duty [Maurer] (compare Mal 2:5, 6). Malachi's function was that of a reformer, leading back the priests and people to the law (Mal 4:4).

Matthew Henry's Concise Commentary

2:1-9 What is here said of the covenant of priesthood, is true of the covenant of grace made with all believers, as spiritual priests. It is a covenant of life and peace; it assures all believers of all happiness, both in this world and in that to come. It is an honour to God's servants to be employed as his messengers. The priest's lips should not keep knowledge from his people, but keep it for them. The people are all concerned to know the will of the Lord. We must not only consult the written word, but desire instruction and advice from God's messengers, in the affairs of our souls. Ministers must exert themselves to the utmost for the conversion of sinners; and even among those called Israelites, there are many to be turned from iniquity. Those ministers, and those only, are likely to turn men from sin, who preach sound doctrine, and live holy lives according to the Scripture. Many departed from this way; thus they misled the people. Such as walk with God in peace and righteousness, and turn others from sin, honour God; he will honour them, while those who despise him shall be lightly esteemed.