1.

His foundation is in the holy mountains.

Title. A Psalm. Hebrew. mizmor. App-65 .
Song. Hebrew. shir . App-65 .
for the sons of Korah: i.e. of or by them. This title is repeated in the sub-scription after Psalms 87:7 , to emphasise the occasion of its use in bringing up the Ark to Zion by David (951BC, a Sabbatic year). See note there, and on Title of Psalms 24 .
His: i.e. Jehovah's (which He has laid in Zion).
holy. See note on Exodus 3:5 .

2.

The LORD loveth the gates of Zion more than all the dwellings of Jacob.

The LORD. Hebrew. Jehovah. App-4 .
Zion. See App-68 .
Jacob. Israel viewed in connection with the natural seed, and with material blessings. See notes on Genesis 32:28 ; Genesis 43:6 ; Genesis 45:26 , Genesis 45:28 .

3.

Glorious things are spoken of thee, O city of God. Selah.

God. Hebrew. ha -' Elohim = the [true] God. App-4 .
Selah. Connecting the first alternation with the second, showing that it is to be a repeated alternation.

4.

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 = pride, or haughtiness. Used as name for Egypt (by Figure of speech Polyonymia, App-6 ), as in Psalms 89:10 ; Isaiah 51:9 . Compare Job 9:13 with Job 26:12 , not the same word as in Joshua 2 .
Ethiopia. Supply Ellipsis of the verb "say": "Tyre with Ethiopia [say]" this, &c.

5.

And of Zion it shall be said, This and that man was born in her: and the highest himself shall establish her.

of = to.
man. Hebrew. 'ish .
the HIGHEST = the MOST HIGH. Hebrew. 'Elyon. App-4 .

6.

The LORD shall count, when he writeth up the people, that this man was born there. Selah.

writeth up = enrolleth.
people = peoples.
That. Instead of "That", supply "[and say] this one", &c.
Selah. Connecting the last repetition of the alternation, and completing the Structure. Thus, both the Selahs in this Psalm are structural.

7.

As well the singers as the players on instruments shall be there: all my springs are in thee.

the singers = they that shout.
the players on instruments = they that dance, as in bringing up the Ark. See note on the subscription.
shall be there. Supply Ellipsis : "[shall say of Zion]".
springs = fountains: i.e. fountains of delight.
A Song, &c. Repeated from the title. Compare Psalms 45 for a similar repetition.
to the chief Musician. See App-64 .
upon Mahalath Leannoth = relating to the shoutings with dancings in bringing up the Ark to Zion (2 Samuel 6:12-15 ; and 1 Chronicles 15:25-29 ). As in Judges 21:21 , Judges 21:23 (compare Revised Version), and see App-65 .