Job 38:21

The verse is ironical,

Thou knowest; for thou wast then born,

And the number of thy days is great.

The words "thou knowest" refer to the question, Job 38:19, Which is the way …? Job knows the way to the place of light, for he was born contemporary with it; he is as old as the dayspring which morning by morning has overspread the earth since creation's dawn.

"Light is considered here, as in Genesis 1, to be a natural force, with an independent existence, apart from the heavenly luminaries that transmit it. And in this, as is well known, modern investigation coincides with the direct perceptions of antiquity" (Schlottmann, Comm. on Job, p. 468). To this remark it has to be added that in the present passage "darkness" also, no less than light, is regarded as a natural force, with an independent existence, and a "place" where it abides, contiguous to light. Science, to which Scripture is taught to look so humbly for approval, will no doubt confirm this representation also.