John Gill

All the kings of the earth shall praise thee, O Lord,.... Or "let them confess", or "praise thee" (s); a wish or prayer. Not only the kings known to David, as Kimchi limits it; or that lived in his days, as Hiram and others; but in the latter day, when they shall come to Zion, the church, and be nursing fathers to it, and shall serve and worship the King Messiah, Isa 49:23; when they hear the words of thy mouth; either the promises of it fulfilled not only with respect to David; but the Messiah, and his church and people, in the latter day, even the glorious things spoken thereof: or the doctrines of the Gospel, which are the words of his mouth, and more desirable than thousands of gold and silver; and which, when kings shall hear so as to understand, they will praise the Lord for them; see Isa 52:15. The Targum is, "the words of thy praise.'' (s) "confiteantur tibi", V. L. Pagninus, Montanus.