Isaiah 66:21

And I will also take of them for priests
That is, of the Gentiles, the brethren brought as an offering to the Lord; and therefore must respect Gospel times, when the Aaronic priesthood would be changed and cease, which admitted not of Gentiles, nor any of any other tribe in Israel, but the tribe of Levi; nor is this to be understood of the spiritual priesthood common to all believers, ( 1 Peter 2:5 1 Peter 2:9 ) ( Revelation 1:6 ) ( 5:10 ) since of those converted Gentiles brought, not all, but only some of them, would be taken for priests; and therefore can only be interpreted of the ministers of the word, who, in Old Testament language, are called priests, though never in the New Testament; but elders, bishops, overseers, pastors, and teachers. The first preachers of the Gospel were Jews, as the twelve apostles, the seventy disciples, Paul and Barnabas, and others; but when the Gospel was preached, and churches planted in the Gentile world, then priests, or pastors, or elders, were taken out from among them, and ordained over the churches everywhere; and which have continued, more or less, ever since; and will be more abundant in the latter day; whose work and office is not to offer up slain beasts, as the priests of old; but to point to the sacrifice of Christ, to the Lamb of God, that takes away the sins of men; and to teach the knowledge of crucified Christ, and the several doctrines and duties of the Christian religion, as the priests formerly taught the knowledge of the law, ( Malachi 2:7 ) : and for Levites, saith the Lord;
this still more clearly shows that the prophecy belongs to the Gospel dispensation, and is to be understood figuratively and spiritually; for none but those of the tribe of Levi could be taken for Levites in a literal sense; but here Gentiles are said to be taken for such, and design men in Gospel churches. The Levites, as their name signifies, were such as were "joined" to others; they ministered to the priests, and assisted them, and had the charge of the temple, and the vessels of it, to whom deacons now answer; who are helps and assistants to the ministers of the word: their business is to serve tables, and to take care of the secular affairs of the church; so that this is a prophecy of the churches in the latter day being truly organized, and filled with proper officers, as well as with numerous members.