Augustine. Exposition on the Book of Psalms. Schaff, Philip (editor). New York: Christian Literature Publishing Co, 1886. Nicene and Post-Nicene Church Fathers: Series 1: Volume VIII. Re-published 2014, Catholic Way Publishing. Kindle electronic edition, ISBN-13: 978-1-78379-372-3.
Augustine begins his comments on Psalm 122 with a brief but eloquent reflection on the fact that different loves compel us in different directions (Augustine Psalms, loc. 340178, par. 1). The Psalm, as a song of ascent, calls the reader to ascend toward a heavenly home. For this reason, verses 1 and 2 speak of being glad at the opportunity to go to Jerusalem, to God's house (Augustine Psalms, loc. 340188, par. 3). Augustine refers to Jesus' words of Jerusalem which kills the prophets. He urges that we should not look fondly on the earthly city, but on the heavenly Jerusalem. Verse three identifies it as a city which is being built. Augustine allegorizes this verse, saying the building has to do with God building up his people in faith (Augustine Psalms, loc. 340199, par. 4). As an earthly building tends to settle towards its foundation, a heavenly building should tend toward the heavenly realms.
The heavenly place, built as a city, calls for a "partaking" "in the same" (Augustine Psalms, loc. 340214, par. 5). This "same" Augustine takes to be Jesus, the one who is the same forever. Augustine further notes that there is stability to be found in Jesus, as he never changes (Augustine Psalms, loc. 340219, par. 6).
Verse four describes "the tribes" going up to this heavenly city (Augustine Psalms, loc. 340224, par. 7). Augustine notes that Israel, with its twelve tribes, just like any place with population divisions, would have good and bad tribes, and within the tribes good and bad people (Augustine Psalms, loc. 340230, par. 8). Those who are good go up to Jerusalem confessing God's name. Augustine considers these to be the true Israelites.
In verse five there are judgment seats (Augustine Psalms, loc. 340240, par. 9). Augustine considers the implications of the seats. They seem to be in God's presence, but they are seats from which some who go up will sit, issuing the judgment of God himself (Augustine Psalms, loc. 340245, par. 9).
The seats, or those seated on the seats, in verse six, are called to pray about the peace of Israel (Augustine Psalms, loc. 340255, par. 10). Augustine understands the essence f the things for peace to be in their doing charitable acts. These deeds lead to a condition of plenty (Augustine Psalms, loc. 340260, par. 11). The greatest plenty is eternal life, what God gives to make a man rich.
Verse seven speaks directly of peace as the characteristic of Jerusalem's strength (Augustine Psalms, loc. 340270, par. 12). Peace, like love, my be very strong, even impossible to overcome. This is how God accomplishes his plans. Therefore, in verse 9, the Psalmist seeks good things, but because of God's house, not because of his own desires (Augustine Psalms, loc. 340285, par. 14). We go up to the heavenly Jerusalem because God is good.