Albert Barnes Commentary Job 37:3

"He sendeth it forth under the whole heaven, And his lightening unto the ends of the earth." — Job 37:3 (ASV)

He directeth it under the whole heaven - It is under the control of God, and He directs it where He pleases. It is not confined to one spot, but seems to be complaining from every part of the heavens.

And his lightning - Margin, as in Hebrew “light.” There can be no doubt that the lightning is intended.

Unto the ends of the earth - Margin, as in Hebrew “wings.” The word “wings” is given to the earth from the idea of its being spread out or expanded like the wings of a bird (Ezekiel 7:2). The earth was spoken of as an expanse or plain that had corners or boundaries (see Isaiah 11:12, note; Isaiah 24:16, note; Isaiah 42:5, note), and the meaning here is that God spread the lightning as He pleased over the whole of that vast expanse.