Have mercy upon me, O LORD; for I am weak: O LORD, heal me; for my bones are vexed.
 My soul is also sore vexed: but thou, O LORD, how long?
6:1-3 in thine anger: The writer is suffering from a serious physical infirmity. It is something that he fears he will never recover (v 5). Not only is he concerned about his physical need, but also his spiritual need. He fears God's anger upon him and no one wants God to be angry at them. In his mourning, David cried out to God (as in 38:1). My bones: is the way he describes his physical infirmity. Truly, the Psalmist is hurting and longs for God's mercy.