Psalm 38 also has bones in it! There is definitely something going on. I checked ahead and 5/7 of the penitential Psalms I listed feature some mention of bones — and all the same Hebrew word too, I checked that. I’ve got to do a bit more digging, but there definitely appears to be some kind of connection between the penitent’s bones and repentance.
In Psalm 38, the penitent appears to get no relief from his (or her) suffering. The Psalm ends with a plea for God to come quickly to help. In the previous two penitential Psalms, relief appeared by the end of the Psalm, or, in the case of Psalm 32, relief appeared before the Psalm was even written. But in Ps 38, no relief appears. This lack of relief doesn’t stop the penitent from praying to God and asking for relief. This is a Psalm is twice as long as the previous two penitential psalms. The penitent describes his (or her) sufferings in some detail. The physical health of the penitent seems to be connected with the person’s sin. Of course, this could be descriptive language of a spiritual illness — and some of the afflictions are clearly metaphorical — “I have become like the deaf” or “like a mute,” or “your arrows have pierced me.” I’m not sure that the illness is all spiritual, however. The penitent Psalmist has mentioned health and healing in connection with repentance before in Psalm 6. Plus we have the repeated mention of the bones of the penitent. While this is all possibly metaphorical, I’m not completely convinced it is entirely metaphorical. Sin appears to influence physical health. Confession seems to bring healing.
More things that make you go hmmm.