Do good, O Lord, unto those that be good ... - To the good; to the pious. Let them be under the divine protection. Possibly this is not merely a prayer, but is expressive of the belief of the psalmist as to what would occur under the divine administration - that the favor of God would rest upon his people.
Related Commentaries of Psalms 125:4
Psalms 125:4
4 Do good, O LORD, unto those that be good, and to them that are upright in their hearts.