John Calvin Commentary Psalms 102:3

"For my days consume away like smoke, And my bones are burned as a firebrand." — Psalms 102:3 (ASV)

For my days are consumed like smoke. These expressions are hyperbolic, but they still show how deeply the desolation of the Church ought to wound the hearts of God's people. Therefore, let everyone carefully examine himself on this point. If we do not prefer the Church to all other objects of our concern, we are unworthy of being counted among her members. Whenever we encounter such forms of expression, let us remember that they reproach our slothfulness in not being affected by the afflictions of the Church as we ought.

The Psalmist compares his days to smoke, and his bones to the stones of the hearth, which, over time, are consumed by the fire. By bones he means human strength. And, if people were not devoid of feeling, such a melancholy spectacle of God's wrath would surely have the effect of drying up their bones and wasting away all their vigor.