Have mercy on me, O God, according to your unfailing love; according to your great compassion blot out my transgressions. Wash away all my iniquity and cleanse me from my sin. For I know my transgressions, and my sin is always before me. Against you, you only, have I sinned and done what is evil in your sight, so that you are proved right when you speak and justified when you judge. Surely I was sinful at birth, sinful from the time my mother conceived me. Surely you desire truth in the inner parts teach me wisdom in the inmost place. Cleanse with me hyssop, and I will be clean; wash me, and I will be whiter than snow.