(Verse 13) Sing to the Lord, praise the Lord, for he has delivered the soul of the poor from the hand of the wicked. The one who is poor in spirit and does not have riches, which have received their consolation in this world, about which Paul also speaks: Only that we should be mindful of the poor (I Cor. 13), when he has obtained vengeance from the Lord, praises the Lord in spirit, and boasts of being delivered from the hand of the wicked. However, all this happens not by our merit, but by the grace of Him who freed the poor, and it does not have the riches of the falling pride, but the humility of the freed poor.
[AD 420] Jerome on Jeremiah 20:13