Who hath divided a water-course for the overflowing of waters - That is, for the waters that flow down from the clouds. The idea seems to be this, that the waters of heaven, instead of pouring down in floods, or all coming down together, seemed to flow in certain canals formed for them; as if they had been cut out through the clouds for that purpose. The causes of rain, the manner in which water was suspended in the clouds, and the reasons why the rain did not come down altogether in floods, early attracted attention, and gave occasion to investigation. The subject is more than once referred to in this book; see the notes at Job 26:8.
Or a way for the lightning of thunder - For the thunder-flash. The idea is this: a path seems to be opened in the dark cloud for the passage of the flash of lightning. How such a path was made, by what agency or by what laws, was the question proposed for inquiry. The lightning seemed at once to burst through the dark cloud where there was no opening and no sign of a path before, and pursue its zig-zag journey as if all obstructions were removed, and it passed over a beaten path. The question is, who could have traced out this path for the thunder-flash to go in? Who could do it but the Almighty? And still, with all the light that science has cast on the subject, we may repeat the question.

Divided a water-course - The original תעלה tealah, from עלה alah, to ascend, may signify rather a cloud, or clouds in general, where the waters are stored up. I cannot see how the overflowings or torrents of water can be said to ascend any other way than by evaporation; and it is by this Divine contrivance that the earth is not only irrigated, but even dried; and by this means too much moisture is not permitted to lie upon the ground, which would not only be injurious to vegetation, but even destroy it. But query, may not a waterspout be intended?
A way for the lightning of thunder - "A path for the bolt of thunder." God is represented as directing the course even of the lightning; he launches the bolt, and makes the path in which it is to run. To grasp, manage, and dart the thunderbolt or lightning, was a work which heathenism gave to Jupiter, its supreme god. None of the inferior deities were capable of this. But who can thunder with a voice like the Almighty? He is The Thunderer.

Who hath divided a watercourse for the overflowing of waters,.... For a very large shower of rain, as the Vulgate Latin version: for this is not to be understood of an aqueduct, channel, or canal made on earth, either for the draining of waters off of land overflowed thereby, or for the conveyance of it to different parts to overflow it; such as were cut out of the Nile in Egypt, for the overflowing of the land, to make it fruitful; such may be and have been made by men: but of a watercourse in the air or atmosphere, as a canal or channel, for the rain to come down upon the earth; and this is the work of God, and him only, who directs and steers the course of rain, that it falls regularly and gently, not in spouts and floods, but in drops larger or lesser, on what spot of ground, or part of the earth, he pleases: and if what Jarchi says true, that every drop has its course, its canal, through which it passes, it is still more wonderful;
or a way for the lightning of thunder: which generally go together, and are of God. His fire and voice, and for which he makes a way, by which they burst and break forth out of the cloud, and their course is directed by him under the whole heavens; see Job 28:26. So the Gospel, compared to rain and lightning, has its direction and its course steered to what part of the world, he pleases; see Psalm 19:4.

Hitherto God had put questions to Job to show him his ignorance; now God shows his weakness. As it is but little that he knows, he ought not to arraign the Divine counsels; it is but little he can do, therefore he ought not to oppose the ways of Providence. See the all-sufficiency of the Divine Providence; it has wherewithal to satisfy the desire of every living thing. And he that takes care of the young ravens, certainly will not be wanting to his people. This being but one instance of the Divine compassion out of many, gives us occasion to think how much good our God does, every day, beyond what we are aware of. Every view we take of his infinite perfections, should remind us of his right to our love, the evil of sinning against him, and our need of his mercy and salvation.

waters--Rain falls, not in a mass on one spot, but in countless separate canals in the air marked out for them.
way for the lightning-- (Job 28:26).

Overflowing - For the showers of rain which come down orderly, and gradually, as if they were conveyed in pipes or channels; which, without the care of God's providence, would fall confusedly, and overwhelm the earth. Lightning - For lightning and thunder? Who opened a passage for them out of the cloud in which they were imprisoned? And these are joined with the rain, because they are commonly accompanied with great showers of rain.