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 considers the theme of Psalm 125 to be that of raising our minds to God rather than fixing them on human instability (Augustine Psalms, loc. 340456, par. 1). The people who trust in the Lord (v. 1), dwelling in Jerusalem (v. 2), have security. Augustine does not consider it possible that these are dwellers in the earthly Jerusalem, but that they look to their heavenly home (Augustine Psalms, loc. 340462, par. 3). This, in verse two, is the city with mountains around it, which Augustine identifies as "preachers of truth, whether Angels, or Apostles, or Prophets" (Augustine Psalms, loc. 340472, par. 4). These are the mountains which receive peace from the Lord. He, as Augustine had noted earlier in the Psalms, is the one who shines light on the mountains (Augustine Psalms, loc. 340481, par. 5). He is the one who guards his people forever.
Verse three speaks of the Lord's work of removing the rod of the ungodly from God's righteous people. Augustine takes this to be a work God accomplishes through His Church, which God uses in conflict to the works of the ungodly (Augustine Psalms, loc. 340510, par. 7). He goes on to describe people in their struggle as they work within their various vocations. While there remain conflicts between the godly and ungodly, in the last day, Christ will show his victory over the ungodly (Augustine Psalms, loc. 340539, par. 8). This is the prayer of the Psalmist in verse four. The Lord must lead his people (v. 5) in truth and joy (Augustine Psalms, loc. 340544, par. 10). Augustine sees the hope of the Christian to be bound up with the peace of Christ leading his people.