Adam Clarke on Job 19:20

My bone cleaveth to my skin - My flesh is entirely wasted away, and nothing but skin and bone left.

I am escaped with the skin of my teeth - I have had the most narrow escape. If I still live, it is a thing to be wondered at, my sufferings and privations have been so great. To escape with the skin of the teeth seems to have been a proverbial expression, signifying great difficulty. I had as narrow an escape from death, as the thickness of the enamel on the teeth. I was within a hair's breadth of destruction; see on Job 19:11 (note).