You clearly see the pain and the sorrow, the misery of the victims. God weighs that in his hand. He is closely involved with that. It makes one think of Lady Justice with the scale: it is about doing justice. On the other hand, the weak entrust themselves to God. They count on God to do justice. He is the Helper of the orphans—the most vulnerable in society. We see a two-sided relationship here: God and his people. See Psalm 68:5: Lord…Father of the fatherless and protector of widows is God in his holy habitation.
The author calls fervently upon the Lord; he makes a strong appeal. And now he utters a confession. But then, faith must be strong. After all, the facts still show the opposite: the Lord does not yet intervene. See also Proverbs 11:31: If the righteous is repaid on earth, how much more the wicked and the sinner!
In any case, the author may not appoint himself as a judge. Romans 12:9 says, Beloved, never avenge yourselves, but leave it to the wrath of God, for it is written, Vengeance is mine, I will repay, says the Lord.
14 But you do see, for you note mischief and vexation, that you may take it into your hands; to you the helpless commits himself; you have been the helper of the fatherless.