Psalm 14:7

O that the salvation of Israel [were come] out of Zion!
&c.] By whom is meant the Messiah, the Saviour of Israel, of all the elect of God, whether Jews or Gentiles; and who is so called, because the salvation of them was put into his hands, and he undertook it; and because he is the Captain and Author of it, and it is in him, and in no other. He was to come out of Zion, out of Judea, from among the Jews; Zion being, as Kimchi observes, the head of the kingdom of Israel; see ( Romans 11:26 ) . Accordingly Christ did come of the Jews, and salvation was of them, ( Romans 9:4 Romans 9:5 ) ( John 4:22 ) ; and for his coming from hence, or for his incarnation, the psalmist most earnestly wishes: he was one of those kings, prophets, and righteous men, that desired to see the days of the Messiah, ( Matthew 13:17 ) ( Luke 10:24 ) . And what might move him so vehemently to wish for it, at this time, might be the sad corruption and depravity of mankind he had been describing, and the afflicted and distressed state of the saints;

when the Lord bringeth back the captivity of his people.
The people of God are, in their unregeneracy, in a state of captivity to sin, Satan, and the law; the work of the Messiah, when he came, was to proclaim liberty to the captives, to set them free, to deliver them from their spiritual bondage: and this Christ has done; he has redeemed his people from all their sins, and from the curse of the law, and from the power of Satan, and has led captivity captive; and which has justly occasioned great joy in the redeemed ones, according to this prophecy:

Jacob shall rejoice, [and] Israel shall be glad;
that is, the posterity of Jacob and Israel; not his natural, but spiritual seed, such who are the true sons of Jacob, Israelites indeed; these having faith and hope in the plenteous redemption of Christ, rejoice in the view of their interest in it; they the song of redeeming love now, and these ransomed ones will hereafter come to Zion with joy, and everlasting joy upon their heads. The Jews refer this to the times of the Messiah ^F3.