Albert Barnes Commentary Psalms 9:12

"For he that maketh inquisition for blood remembereth them; He forgetteth not the cry of the poor." — Psalms 9:12 (ASV)

When he makes inquisition for blood - When he “inquires” after blood; that is, when he comes forth with this view, namely, for purposes of punishment. There is an allusion here to such passages as Genesis 9:5: And surely your blood of your lives will I require; at the hand of every beast will I require it, and at the hand of man. The idea is that when blood was shed in murder, God would seek out the murderer; he would require satisfaction from the one who had shed the blood; he would punish the offender. This language then becomes equivalent to seeking punishment for murder, and then for sin in general. The representation here is of God going forth in the capacity of an executioner of his own laws to inflict punishment on the guilty.

He remembers them - “He remembers,” says Prof. Alexander, “the bloods or murders,” since the word blood, as in Psalm 5:6, is in the plural—bloods. The better interpretation, however, is that the word “them” here refers to the oppressed and the afflicted—for that is the main idea in the passage .

When he goes forth in the earth to execute judgment on the wicked—when he cuts them down in his wrath, when he sweeps them away as with a flood—the punishment will not be indiscriminate. He will then mark the oppressed, the afflicted, the persecuted, the troubled, and the sad, and will interpose to save them, delivering them from the storms of wrath. The idea, then, is that the righteous will not be forgotten; that even in the most fierce and awful of his dispensations he will still regard them and interpose to save them.

He forgets not the cry of the humble - Margin: afflicted. The margin expresses the true idea. The reference is not to the humble in the common sense of that term, but to the afflicted, the oppressed, to those who are in trouble (Psalms 9:9). He will then remember the cry which, in their afflictions, they have long been sending up to him.