Job 28:5

“[As for] the earth, out of it cometh bread, etc.] 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, (<19A414>Psalm 104:14,15). The West Indians formerly made their bread of roots of the earth, particularly one called “jucca” f965; so Caesar’s soldiers in distress made bread of a root called “chara”, steeped in milk f966: and under it is turned up as it were fire; coal, which is fuel for fire; for, as in the earth are mines for gold and silver, iron and brass, out…”

“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).”

“As for the earth, out of it cometh bread - That is, it produces food, or the materials for bread. The idea of Job seems to be, that it was proof of great wisdom and skill on the part of man that he had carried the arts of agriculture so far. The earth in producing grain, and the arts of husbandry, were illustrative of wisdom and skill, but they did not impart the wisdom about the government of God which was desired. That was reserved to be imparted more directly by God himself, Job 28:23 ff. And under it is turned up as it were fire - That is, on being turned up it discloses precious stones that seem to glow like coals of fire. This is the obvious sense of this passage, though a different…”

“Fire - Coals, and brimstone, and other materials of fire. Unless this refer, as some suppose, to a central fire. Job 28:6”

“28:5 Miners melted rock by burning a fire in a mine for days or even weeks to melt out the ore. Some alternated fire with cold water to split the rocks.”

“out of it: Gen 1:11, Gen 1:12, Gen 1:29; Psa 104:14, Psa 104:15; Isa 28:25-29 fire: Eze 28:13, Eze 28:14 Job 28:6”

“5 The earth-from it cometh forth bread, And beneath it is turned up like fire. 6 The place of the sapphire are its stones, And it containeth gold ore. 7 The way, that no bird of prey knoweth, And the eye of the hawk hath not gazed at, 8 Which the proud beast of prey hath not trodden, Over which the lion hath not walked. Job 28:5 is not to be construed as Rosenm.: ad terram quod attinet, ex qua egreditur panis, quod subtus est subvertitur quasi igne; nor with Schlottm.: (they swing) in the earth, out of which comes bread, which beneath one turns about with fire; for Job 28:5 is not formed so that the Waw of ותחתּיה could be Waw apod., and ארץ cannot signify "in the interior of the earth" as…”