As for the earth, out of it comes bread, but underneath it is turned up as by fire.
Here Job shows, 1. What a great way the wit of man may go in diving into the depths of nature and seizing the riches of it, what a great deal of knowledge and wealth men may, by their ingenious and industrious searches, make themselves masters of.
Commenting on Job 28:1-11
As for the earth, out of it cometh bread,.... That is, bread corn, or corn of which bread is made particularly wheat; which falling, or being cast into the earth, rises up and brings forth fruit, and, when ground into flour, makes fine bread; and to this same original the psalmist ascribes bread, which strengthens man's heart, Psa 104:14.
Its fertile surface yields food; and yet "beneath it is turned up as it were with fire." So PLINY [Natural History, 33] observes on the ingratitude of man who repays the debt he owes the earth for food, by digging out its bowels. "Fire" was used in mining [UMBREIT]. English Version is simpler, which means precious stones which glow like fire; and so Job 28:6 follows naturally (Eze 28:14).