For the Lord will judge his people - He will interpose in their behalf by his judgments, or by directing the course of events in their favor. This language is copied literally from Deuteronomy 32:36 : "For the Lord shall judge his people, and repent himself for his servants." It is there a part of the song of Moses after the journey through the wilderness, after smiting the kings of the Amorites and of Bashan; and when, delivered from their enemies, the Israelites had come to the borders of the promised land, Deut. 31. The language was, therefore, especially appropriate to the design of this psalm.
And he will repent himself concerning his servants - In behalf of his people. That is, he will do as if he repented, or had changed his mind. He will stay his judgments. He will not suffer his people to be destroyed. He will not permit the judgments which seemed to threaten their entire ruin to be carried out to the full. They shall be arrested midway as if God had then changed his mind. Of course, all this is language accommodated to human weakness, and to the manner of speaking among people.

The Lord will judge his people - He will do them justice against their enemies.

For the LORD will (f) judge his people, and he will repent himself concerning his servants.
(f) That is, govern and defend his people.

For the Lord will judge his people,.... Rule and govern, protect and defend them; plead their cause, and avenge them of their enemies; judge between them, distinguish them by his care and providence, make them visible, so that others shall see the difference between them; especially at the last day, when he will judge them, and, as the righteous Judge, give them the crown of righteousness. Or "though the Lord judges his people" (m); chastises them in a fatherly way, that they may not be condemned with the world;
and, or "yet" (n);
he will repent himself concerning his servants; of the evil of affliction he has brought upon them; he will change the course of his providential dealings with them, according to his unchangeable will; and turn their adversity into prosperity, and their mourning into joy: some render it, "he will be entreated for his servants" (o); he will hear prayer on their account, and save them out of their afflictions; or, as others, "he will comfort himself concerning his servants" (p); take pleasure in them and their prosperity, comfort them, and take delight in so doing. The Targum of the whole is,
"for the Lord will judge the judgment of his people by his word, and to his righteous servants will return in his mercies.''
(m) "quod si", Junius & Tremellius; "nam etsi", Piscator. (n) "Tamen", Piscator; "mox", Junius & Tremellius. (o) "deprecabitur", V. L. "sinet se deprecari", Tirinus. (p) "Solatium reportabit", Tigurine version.

will judge--do justice (Psalm 72:2).
repent himself--change His dealings (Psalm 90:13).

Judge - Will in due time plead the cause of his people. Repent - He will recall that severe sentence which for their sins he had passed upon them.