Psalms 51:3

Psalms 51:3. For I acknowledge my transgressions: and my sin is ever before me.

He had tried to forget it, but he could not, for it haunted him wherever he went. He had put it behind his back, but now it had got in front of his eyes.

It seemed as if it were painted on his eyeballs, and he could not see without seeing through his sin. This is how God makes men repent, - how he makes sin to be like gall and wormwood to them.