His foundation is in the holy mountains.
Its foundation — The foundation of the temple of God.
 The LORD loveth the gates of Zion more than all the dwellings of Jacob.
Zion — That is, Zion itself, or Jerusalem, which was built upon and near mount Zion. He saith Zion rather than Jerusalem, to intimate that he loved Jerusalem for Zion's sake, or for the temple, which he chose for his peculiar dwelling place.
 I will make mention of Rahab and Babylon to them that know me: behold Philistia, and Tyre, with Ethiopia; this man was born there.
Rahab — Egypt, so called, either from its pride or natural strength.
Babylon — Under these two and Philistia, the constant enemies of Israel, he seems to understand all the enemies of the church of God, who shall now be not only reconciled but united to them.
Arabia — The nations on every side of them, for Tyre was on the north, Arabia on the South; those nearest to them, and those more remote from them.
 And of Zion it shall be said, This and that man was born in her: and the highest himself shall establish her.
Zion — Of Jerusalem, or the church of God.
Said — It shall be acknowledged.
Man — Heb. Man and man, all sorts of men without difference of nations.
Establish — And this shall not be a transient, but a lasting work; Zion shall continue in its strength and fertility because the Almighty God is her founder and protector.
 The LORD shall count, when he writeth up the people, that this man was born there. /*Selah*/.
When — When God, the maker and governor of this city shall take a survey of all his citizens. It is an allusion to princes or governors of cities that use to write and keep a register of all their people.
 As well the singers as the players on instruments shall be there: all my springs are in thee.
Singers — There shall be great rejoicing and praising God, both with vocal and instrumental musick, for this glorious work of the conversion of the Gentiles. He describe's evangelical worship, by legal phrases and customs, as the prophets frequently do.
In thee — In Zion or the church. These words may be here added as the burden of the song, which these singers are supposed to have sung, in the name of all the people of God. All our desires and delights are in thee, all the springs of mercy, grace, and glory, flow to us only in and thro' thee.