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 notes that Psalm 127 is attributed to Solomon. Though Solomon himself fell prey to his sinful desires, Augustine understands that his sin does not invalidate him entirely, or all humans would be of no account (Augustine Psalms, loc. 340655, par. 1). It is, after all, in verse one, the Lord who builds the house. Augustine allegorizes this to refer to the Church. Though apostles, prophets, and other humans labor, the growh comes from God (Augustine Psalms, loc. 340665, par. 1).
Augustine also considers that the Lord is building a city. This leads him to discuss the role of bishops. He sees it as a high position of service and responsibility, guarding the hearts and souls of the people (Augustine Psalms, loc. 340675, par. 2) The bishops still do not guard people of their own accord, but as the Lord directs (v. 1).
Verse two speaks of the folly of arising in the dark to work. Augustine takes this to speak of Christ as the light of the world. We therefore rise to follow Christ, rather than to work in the dark (Augustine Psalms, loc. 340689, par. 3). Augustine continues to describe the rising of Chrsit after his rest "on the cross" rather than in the tomb (Augustine Psalms, loc. 340699, par. 4). The cycle of resting and rising, as we are told of the rest of God's beloved (v. 3), becomes a message of death and resurrection (Augustine Psalms, loc. 340704, par. 4).
Verse three continues by comparing the beloved of the Lord to children born. Augustine again ties the concept of earthly birth to the work of the Church in the cycle of birth, death, and resurrection (Augustine Psalms, loc. 340714, par. 5). Verse four, then, speaking of children as arrows in the hand of a mighty one, naturally suggests God as the mighty one, placing his children near and far (Augustine Psalms, loc. 340719, par. 6).
Augustine also sees the work of revelation, carried out by the apostles and prophets, to be something built by the Lord, and propelled by His hand (Augustine Psalms, loc. 340734, par. 7). Verse five then speaks of the blessedness of desiring God's work, rather than our temporal pleasures. Augustine concludes, then, that our life is to be spent seeking God's glory (Augustine Psalms, loc. 340744, par. 8).