It devours patches of his skin; the firstborn of death devours his limbs.
Bildad here describes the destruction itself which wicked people are reserved for in the other world, and which, in some degree, often seizes them in this world. Come, and see what a miserable condition the sinner is in when his day comes to fall. I.
Commenting on Job 18:11-21
His confidence shall be rooted out of his tabernacle,.... That which his confidence was placed in, his wealth and riches, his family, particularly his children, in all which he placed his confidence of future prosperity and happiness; these should be all taken away from him, and his house cleared of them all; or his good, sound, and healthful constitution, on account of which he promised...
UMBREIT has "he" for "it," that is, "in the rage of hunger he shall devour his own body"; or, "his own children" (Lam 4:10). Rather, "destruction" from Job 18:12 is nominative to "devour." strength--rather, "members" (literally, the "branches" of a tree). the first-born of death--a personification full of poetical horror.