I. Here is a recital of the covenant God made with that sacred tribe, which was their commission for their work and the patent of their honour: The Lord of hosts sent a commandment to them, for the establishing of this covenant (v. 4), for his covenant is said to be the word which he commanded (Ps. cv. 8); and he sent this commandment by the prophet at this time for the re-establishing of it, that it might not be cut off for their persisting in the violation of it. Let the sons of Levi know then (and particularly the sons of Aaron) what honour God put upon their family, and what a trust he reposed in them (v. 5): My covenant was with him of life and peace. Besides the covenant of peculiarity made with all the house of Israel, there was a covenant of priesthood made with one family, that they should do the services, and, upon condition of that, should enjoy all the privileges, of the priest's office—that, as Israel was a peculiar nation, a kingdom of priests, so the house of Aaron should be a family of priests, set apart for the service and honour of God, to bear up his name in that nation, as they were to bear up his name among the nations; both the one and the other, in different degrees, were to give glory unto God's name, v. 2. God covenanted with them as his menial servants, obliged them to do his work and promised to own and accept them in it. This is called his covenant of life and peace, because it was intended for the support of religion, which brings life and peace to the souls of men—life to the dead, peace to the distressed, or because life and peace were by this covenant promised to those priests that faithfully and conscientiously discharged their duty; they shall have peace, which implies security from all evil, and life, which comprises the summary of all good. 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 life and peace, everlasting peace, everlasting life, all happiness both in this world and in that to come. This covenant was made with the whole tribe of Levi when they were distinguished from the rest of the tribes, were not numbered with them, but were taken from among them and appointed over the tabernacle of testimony (Num. i. 49, 50), by virtue of which appointment God says (Num. iii. 12), The Levites shall be mine. It was made with Aaron when he and his sons were taken to minister unto the Lord in the priest's office, Exod. xxviii. 1. Aaron is therefore called the saint of the Lord, Ps. cvi. 16. It was made with Phinehas and his family, a branch of Aaron's, upon a particular occasion, Num. xxv. 12, 13. And there the covenant of priesthood is called, as here, the covenant of peace, because by it peace was made and kept between God and Israel. These great blessings of life and peace, contained in that covenant, God gave to him, to Levi, to Aaron, to Phinehas; he promised life and peace to them and their posterity, entrusted them with these benefits for the use and behoof of God's Israel; they received that they might give, as Christ himself did, Ps. lxviii. 18. Now, for the further opening of this covenant, observe, 1. The considerations upon which it was grounded: It was for the fear wherewith he feared me, and was afraid before my name. The tribe of Levi gave a signal proof of their holy fear of God, and their reverence for his name, when they appeared so bravely against the worshippers of the golden calf (Exod. xxxii. 26); and for their zeal in that matter God bestowed this blessing upon them and invited them to consecrate themselves unto him. Phinehas also showed himself zealous in the fear of God and his judgments when, to stay the plague, he stabbed Zimri and Cozbi, Ps. cvi. 30, 31. Note, Those, and those only, who fear God's name, can expect the benefit of the covenant of life and peace; and those who give proofs of their zeal for God shall without fail be recompensed in the glorious privileges of the Christian priesthood. Some read this, not as the consideration of the grant, but as the condition of it: I gave them to him, provided that he should fear before me. If God grant us life and peace, he expects we should fear before him. 2. The trust that was lodged in the priests by this covenant, v. 7. They were hereby made the messengers of the Lord of hosts, messengers of that covenant of life and peace, not mediators of it, but only messengers, or ambassadors, employed to treat of the terms of peace between God and Israel. The priests were God's mouth to his people, from whom they must receive instructions according to the lively oracles. This was the office to which Levi was advanced; because, in his zeal for God, he did not acknowledge his brethren, nor know his own children, therefore they shall teach Jacob God's judgments, Deut. xxxiii. 9, 10. Note, It is an honour to God's servants to be employed as his messengers and to be sent on his errands. Angels have their name thence. Haggai was called the Lord's messenger. This being their office, observe, (1.) What is the duty of ministers: The priests' lips should keep knowledge, not keep it from the people, but keep it for them. Ministers must be men of knowledge; for how are those able to teach others the things of God who are themselves unacquainted with those things or unready in them? They must keep knowledge, must furnish themselves with it and retain what they have got, that they may be like the good householder, who brings out of his treasury things new and old. Not only their heads, but their lips, must keep knowledge; they must not only have it, but they must have it ready, must have it at hand, must have it (as we say) at their tongue's end, to be communicated to others as there is occasion. Thus we read of wisdom in the lips of him that has understanding, with which they feed many, Prov. x. 13, 21. (2.) What is the duty of the people: They should seek the law at his mouth; they should consult the priests as God's messengers, and not only hear the message, but ask questions upon it, that they may the better understand it and that mistakes concerning it may be prevented and rectified. We are all concerned fully to know what the will of the Lord is, to know it distinctly and certainly; we should be desirous to know it and therefore inquisitive concerning it. Lord, what wilt thou have me to do? We must not only consult the written word (to the law and to the testimony), but must have recourse to God's messengers, and desire instruction and advice from them in the affairs of our souls as we do from physicians and lawyers concerning our bodies and estates. Not but that ministers ought to lay down the law of God to those who do not enquire concerning it, or desire the knowledge of it (they must instruct those that oppose themselves, 2 Tim. ii. 25, as well as those that offer themselves), but it is people's duty to apply to them for instruction, not only to hear, but to ask questions. Watchman, what of the night? Thus if you will enquire, enquire you; see Isa. xxi. 8, 11, 12. People should not only seek comfort at the mouth of their ministers, but should seek the law there; for, if we found in the way of duty, we shall find it the way of comfort.