1 Yahveh, listen to a just cause; pay attention to my cry; hear my prayer –from lips free of falsehood. 2 Let my vindication come from you, because you see what is right. 3 You have tested my heart; you have examined me at night. You have tried me and found nothing evil; I have determined that my mouth will make no mistake.
The psalmist comes from a culture where prayers were designed to manipulate the gods. He rejects that kind of religion. He opens his life for inspection by his Lord. He is not introducing himself to the Lord. So he just asks for fairness. He knows God will do the right thing.