Albert Barnes Commentary Psalms 79:6

"Pour out thy wrath upon the nations that know thee not, And upon the kingdoms that call not upon thy name." — Psalms 79:6 (ASV)

Pour out thy wrath upon the heathen — Punish, as they deserve, the nations that have risen up against your people and have brought desolation upon the land.

The word rendered here "pour out" is used with reference to a cup or vial containing a mixture for people to drink—of intoxication or of poison.

See the notes at Revelation 16:1; Psalms 11:6; and Isaiah 51:17. Compare to Jeremiah 25:15, Jeremiah 25:17; Matthew 20:22; and Matthew 26:39, Matthew 26:42.

That have not known thee — This refers to those who are strangers to you, who are your enemies.

The prayer that God's wrath might be poured upon them was not because they were ignorant of Him, but on account of their wicked conduct toward the people of God.

The phrase that have not known thee is used merely to designate them or to describe their character.

This prayer is not necessarily a prayer for vengeance or in a spirit of revenge; it is simply a prayer that justice might be done to them. It is such a prayer as anyone may offer who is anxious that justice be done in the world.

See remarks on the imprecations in the Psalms, General Introduction, Section 6.

It is not proper, however, to use this as a proof-text that God will punish the “pagan” or consign them to destruction.

The passage obviously has no reference to such a doctrine, whether that doctrine is true or false.

And upon the kingdoms that have not called upon thy name — This refers to the people who do not worship you, particularly those who had invaded the land and made it desolate.