Albert Barnes Commentary Psalms 38:15

"For in thee, O Jehovah, do I hope: Thou wilt answer, O Lord my God." — Psalms 38:15 (ASV)

For in you, O Lord, do I hope - This shows the reason or ground of his patience. He committed his whole cause to God. He believed that God would take care of his reputation and vindicate him. See Psalms 37:5-6.

He had no doubt that He would protect his character, and that, despite the reproaches of his enemies, his true character would finally be made to shine forth, so that all people would see that he had been unjustly slandered.

The exact idea here is expressed, and the sentiment was beautifully and perfectly illustrated, in what is said of the Lord Jesus: Who, when he was reviled, reviled not again; when he suffered, he threatened not; but committed himself to him that judgeth righteously (1 Peter 2:23).

You will hear, O Lord my God - Margin, as in Hebrew: "answer." The idea is that God would answer his prayers, and that his character would, in answer to those prayers, be set right before the world.