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 takes Psalm 144 to speak of God's use of David to overcome Goliath. He particularly mentions the overthrow of Goliath as the devil, and notes that he was defeated using his own weapons (Augustine Psalms, loc. 342438, par. 1).
The body of Christ, in some way, is trained by God for battle. Verse one refers to fingers, which can operate separately and together, showing the unity and diversity in the body of Christ (Augustine Psalms, loc. 342443, par. 2). The warfare we engage in, according to Augustine's reckoning, is that of using mercy and charity to overcome evil. God is seen as our mercy, the one who rescues us. We therefore receive mercy and do good (Augustine Psalms, loc. 342453, par. 3).
In verse three, the Psalmist wonders at the idea that God has made himself known to man (Augustine Psalms, loc. 342458, par. 4). God has valued man so highly that Christ would give himself for us. This is a very high value, especially considering man's nature, passing away (v. 4) (Augustine Psalms, loc. 342463, par. 5).
Verses 5-7 call out to God for a relatively dramatic rescue, with smoke, lightning, and arrows, as he pulls us out of the waters (Augustine Psalms, loc. 342474, par. 6). Augustine observes numerous instances of God reaching to the earth in a way which we might consider dramatic. He is taking action against those who reject him. Those people speak vanity against the Lord and will be defeated (Augustine Psalms, loc. 342493, par. 7).
In verse 10 we are reminded once again that this God is the one who redeems kings, even David. Augustine speaks of David as allegorically referring to Christ, here Christ's body, the Church, which he redeems from all sin, even from the sword (Augustine Psalms, loc. 342504, par. 8). Verse 12 speaks to the intergenerational work of God, as the sons of the Church become part of the Church (Augustine Psalms, loc. 342514, par. 9). These people will have abundance and joy (vv. 13-14). Their years shall not fil, an idea which reminds Augustine of the nature of their life - eternal. Verse 15 calls these blessed people, the people of God (Augustine Psalms, loc. 342529, par. 10).