Psalm 6 is the first penitential psalm, a cry to God for mercy and relief from the consequences of sin. We don’t know David’s exact circumstances, but his pain is acute and overwhelming, so he marshals his prayers and his tears before Yahweh to seek relief. This psalm is offered to the chief musician, for the strings, and “upon the eighth” which may mean for an eight-stringed harp. We have it in order to learn godly sorrow and sure victory.