Charles H. Spurgeon on Psalms 32:3

When I kept silence. When through neglect I failed to confess, or through despair dared not do so, my bones, those solid pillars of my frame, the stronger portions of my bodily constitution, waxed old, began to decay with weakness, for my grief was so intense as to sap my health and destroy my vital energy. What a killing thing is sin! It is a pestilent disease! A fire in the bones! While we smother our sin it rages within, and like a gathering wound swells horribly and torments terribly. Through my roaring all the day long. He was silent as to confession, but not as to sorrow. Horror at his great guilt, drove David to incessant laments, until his voice was no longer like the articulate speech of man, but so full of sighing and groaning, that it resembled to hoarse roaring of a wounded beast. None knows the pangs of conviction but those who have endured them. The rack, the wheel, the flaming fagot are ease compared with the Tophet which a guilty conscience kindles within the breast: better suffer all the diseases which flesh is heir to, than lie under the crushing sense of the wrath of almighty God. The Spanish inquisition with all its tortures was nothing to the inquest which conscience holds within the heart.