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).

     5-9. He describes the promises, and also the conditions of the covenant; Levi's observance of the conditions and reward (compare Nu 25:11-13, Phinehas' zeal); and on the other hand the violation of the conditions, and consequent punishment of the present priests. "Life" here includes the perpetuity implied in Nu 25:13, "everlasting priesthood." "Peace" is specified both here and there. MAURER thus explains it; the Hebrew is, literally, "My covenant was with him, life and peace (to be given him on My part), and I gave them to him: (and on his part) fear (that is, reverence), and he did fear Me," &c. The former portion of the verse expresses the promise, and Jehovah's fulfilment of it; the latter, the condition, and Levi's steadfastness to it (De 33:8, 9). The Jewish priests self-deceivingly claimed the privileges of the covenant, while neglecting the conditions of it, as if God were bound by it to bless them, while they were free from all the obligation which it imposed to serve Him. The covenant is said to be not merely "of life and peace," but "life and peace"; for the keeping of God's law is its own reward (Ps 19:11).

     6. law of truth was in his mouth—He taught the people the truths of the law in all its fulness (De 33:10). The priest was the ordinary expounder of the law; the prophets were so only on special occasions.