This psalm is expressly ascribed to David, though it is not known why it should be classed among the "Songs of Degrees." On the supposition that these were used by the pilgrims in "going up" to Jerusalem to worship, and that they were sung by the way, this psalm would be particularly appropriate, and is one of the very few, in the entire collection of fifteen, that would be appropriate. This psalm evidently was used on some such occasion, and is beautifully suited to such a design. There is no reason to doubt that it is a composition of David, but it is not now possible to ascertain at what period of his life, or on what particular occasion, it was composed. DeWette has endeavored to show that the psalm must have been composed at a later period in the Jewish history than the time of David. His arguments are:
(1) that these "Psalm of Degrees" mostly pertain to a later period, and yet that they are closely connected together in sense;
(2) that the language indicates a later period than the time of David;
(3) that the pilgrimage to Jerusalem was not instituted until a later age than that of David;
(4) that the mention of the "thrones of the house of David" Psalm 122:5 indicates a later age; and
(5) that Jerusalem is represented Psalm 122:3 as a city already built - probably, as DeWette thinks, referring to Jerusalem as rebuilt after the captivity.
It will be found, however, in the exposition of the psalm, that there is no part of it which is not applicable to David and his times.

The satisfaction of a gracious soul in the use of God's ordinances, Psalm 122:1, Psalm 122:2. Description of the internal governmentof Jerusalem, Psalm 122:3-5. Prayers for its peace and prosperity, Psalm 122:6-9.
In the preceding Psalm we find the poor captives crying to God for deliverance; here they are returning thanks that they find they are permitted to return to their own land and to the ordinances of their God.

INTRODUCTION TO PSALM 122
A Song of degrees of David. This is the first of the songs of degrees that bears the name of David: and Kimchi thinks they only were written by him which have his name to them; though he, Abendana, and others, are of opinion that this psalm was composed with a view to the captives in Babylon; who are here represented, and are represented as rejoicing at their going up to Jerusalem, to the solemn feasts there. The inscription in the Syriac version is,
"a "psalm" of David, one of the psalms of ascent, when Cyrus commanded the captivity to go up; spiritually, a promise of good things.''
It seems to be designed for the use of the Israelites, and to be sung by them when they went up to the feasts, three times a year. Some say (a) they sung this by the way, when they carried the firstfruits to Jerusalem.
(a) Weemse's Christ. Synagog. l. 1. c. 6. s. 4. p. 144.

(Psalm 122:1-5) Esteem for Jerusalem.
(Psalm 122:6-9) Concern for its welfare.

A Well-Wishing Glance Back at the Pilgrims' City
If by "the mountains" in Psalm 121:1 the mountains of the Holy Land are to be understood, it is also clear for what reason the collector placed this Song of degrees, which begins with the expression of joy at the pilgrimage to the house of Jahve, and therefore to the holy mountain, immediately after the preceding song. By its peace-breathing (שׁלום) contents it also, however, touches closely upon Psalm 120:1-7. The poet utters aloud his hearty benedictory salutation to the holy city in remembrance of the delightful time during which he sojourned there as a visitor at the feast, and enjoyed its inspiring aspect. If in respect of the לדוד the Psalm were to be regarded as an old Davidic Psalm, it would belong to the series of those Psalm of the time of the persecution by Absalom, which cast a yearning look back towards home, the house of God (Psalm 23:1-6; Psalm 26:1-12, Psalm 55:15; Psalm 61:1-8, and more particularly Psalm 63:1-11). But the לדוד is wanting in the lxx, Codd. Alex. and Vat.; and the Cod Sinait., which has ΤΩ ΔΑΔ, puts this before Psalm 124:1-8, ει ̓ μὴ ὅτι κύριος κ. τ. λ., also, contrary to Codd. Alex. and Vat. Here it is occasioned by Psalm 122:5, but without any critical discernment. The measures adopted by Jeroboam I show, moreover, that the pilgrimages to the feasts were customary even in the time of David and Solomon. The images of calves in Daniel and Bethel, and the changing of the Feast of Tabernacles to another month, were intended to strengthen the political rupture, by breaking up the religious unity of the people and weaning them from visiting Jerusalem. The poet of the Psalm before us, however, lived much later. He lived, as is to be inferred with Hupfeld from Psalm 122:3, in the time of the post-exilic Jerusalem which rose again out of its ruins. Thither he had been at one of the great feasts, and here, still quite full of the inspiring memory, he looks back towards the holy city; for, in spite of Reuss, Hupfeld, and Hitzig, Psalm 122:1., so far as the style is concerned, are manifestly a retrospect.