Albert Barnes Commentary Job 24:21

"He devoureth the barren that beareth not, And doeth not good to the widow." — Job 24:21 (ASV)

He mistreats the barren - The woman who has no children to comfort or support her. He increases her calamity by acts of cruelty and oppression. To be without children, as is well known, was regarded in the patriarchal ages as a great calamity.

And does no good to the widow - See the notes at (Job 24:3). Despite all this, he is permitted to live in prosperity and to die without any visible signs of divine displeasure.