Psalms 87:1

“His foundation is in the holy mountains.] The Jewish writers connect these words with the title of the psalm, and make the sense to be this; “the foundation” or argument “of it”, the psalm, “is concerning the holy mountains” of Zion and Jerusalem; so Aben Ezra, Jarchi, and Kimchi; and the Targum joins them together thus, “by the hands of the sons of Korah is said a song, which is founded by the mouth of the fathers that were of old:” but the words are a part of the song or psalm, which begins in an abrupt manner, just as (<220102>Song of Solomon 1:2) and may be rendered either “its foundation”, or “his foundation”, and refer either to the church, or to the Lord, and the sense is the same…”

“Upon Mahalath--either an instrument, as a lute, to be used as an accompaniment (Leannoth, "for singing") or, as others think, an enigmatic title (see on Psa 5:1, Psa 22:1, and Psa 45:1, titles), denoting the subject--that is, "sickness or disease, for humbling," the idea of spiritual maladies being often represented by disease (compare Psa 6:5-6; Psa 22:14-15, &c.). On the other terms, see on Psa 42:1 and Psa 32:1. Heman and Ethan (see on Psa 89:1, title) were David's singers (Ch1 6:18, Ch1 6:33; Ch1 15:17), of the family of Kohath. If the persons alluded to (Kg1 4:31; Ch1 2:6), they were probably adopted into the tribe of Judah. Though called a song, which usually implies joy (Psa 83:1),…”

“His foundation - This is an abrupt commencement of the psalm. The adjective “his” has been supposed by some to refer to the psalm itself, and this expression has been considered to be a part of the title to the psalm, meaning that the foundation of the psalm is the holy mountain where the praises of God were celebrated; that is Zion. This, however, is a forced and unnatural interpretation. The most obvious explanation is to refer it to God, and the meaning is, that his “foundation,” or that which he had founded and established, to wit, the place for his worship, or for the institutions of religion, was in the holy mountains of Jerusalem. It would seem that the psalmist was contemplating the…”

“Its foundation - The foundation of the temple of God. Psalms 87:2”

“Ps 87 This psalm envisions Jerusalem as the city of God where all the nations are citizens. 87:1 Jerusalem was Israel’s capital and the location of the Temple, God’s earthly palace (see Ps 84).”

“for: or, of His: Ch2 3:1; Isa 28:16; Mat 16:18; Co1 3:10, Co1 3:11; Eph 2:20-22; Pe1 2:4-8 the holy: Psa 48:1, Psa 48:2, Psa 68:16, Psa 121:1; Isa 2:2, Isa 2:3, Isa 56:7; Zac 8:3; Pe2 1:18 Psalms 87:2”

“The poet is absorbed in the contemplation of the glory of a matter which he begins to celebrate, without naming it. Whether we render it: His founded, or (since מיסּד and מוּסּד are both used elsewhere as part. pass.): His foundation (after the form מלוּכה, poetically for יסוד, a founding, then that which is set fast = a foundation), the meaning remains the same; but the more definite statement of the object with שׁערי ציּון is more easily connected with what precedes by regarding it as a participle. The suffix refers to Jahve, and it is Zion, whose praise is a favourite theme of the Korahitic songs, that is intended. We cannot tell by looking to the accents whether the clause is to be taken…”