The clouds poured out waters. As the noun mym, mayim, cannot be taken in the construct state, the verb, I have no doubt, is put transitively; but it makes little difference as to the sense, whether we take this view, or read as if mym, mayim, were in the construct state and the verb passive; that is, whether we read, The clouds poured out waters, or, The waters of the clouds were poured out. The meaning obviously is, that not only the sea and the river Jordan, but also the waters which were suspended in the clouds, yielded to God the honor to which he is entitled, the air, by the concussion of the thunder, having poured forth copious showers. The object is to show, that, to whatever quarter men turn their eyes, the glory of God is illustriously manifested, that it is so in every part of creation, above and beneath, from the height of heaven to the depths of the sea. What history is here referred to is involved in some degree of uncertainty. [1] Perhaps it is that which is recorded in Exodus 9:23; where we are informed, that hail mingled with thunder and lightning was one of the dreadful plagues inflicted upon the Egyptians. The arrows which went abroad are, no doubt, to be taken metaphorically for lightnings. With this verse we are to connect the following, in which it is said, that the voice of the thunder was heard in the air, and that the lightnings illumined the world, so that the earth trembled The amount is, that at the departure of the people from Egypt, ample testimony was borne to the power of God, both to the eyes and the ears of men; peals of thunder having been heard in every quarter of the heavens, and the whole sky having shone with flashes of lightning, while at the same time the earth was made to tremble.

Footnotes

1 - As in the three preceding verses the deliverance of the chosen people from Egypt, and the drying up of the Red Sea, to make a way for them to pass through, are the subjects celebrated, it is very natural to suppose that the 17th and 18th verses refer to the tempestuous rain, the thunder, lightning, and earthquake, by which God testified his wrath against the Egyptians, and by which that ruthless host were filled with dismay, when they went into the midst of the Red Sea after the Israelites. Of these particular circumstances, we have indeed no distinct information in the narrative of Moses; but from a comparison of what is here stated, with what is said in Exodus 14:24, "And it came to pass, that in the morning watch the Lord looked unto the host of the Egyptians through the pillar of fire and of the cloud, and troubled the host of the Egyptians," it seems highly probable that they took place on that occasion. With this corresponds the representation given by Josephus of this part of Jewish History. "As soon as ever the whole Egyptian army was within it, the sea flowed to its own place, and came down with a torrent raised by storms of wind, and encompassed the Egyptians. Showers of rain also came down from the sky, and dreadful thunders and lightning, with flashes of fire. Thunder-bolts also were darted upon them; nor was there any thing which used to be sent by God upon men, as indications of his wrath, which did not happen at that time; for a dark and dismal night oppressed them." -- Antiquities of the Jews, Book II. chapter 16, section 3.

The clouds poured out water - Margin, "The clouds were poured forth with water." The translation in the text is the more correct. This is a description of a storm; but to what particular storm in history does not appear. It was evidently some exhibition of the divine greatness and power in delivering the children of Israel, and may have referred to the extraordinary manifestation of God at Mount Sinai, amidst lightnings, and thunders, and tempests. Exodus 19:16. For a general description of a storm, as illustrating this passage, see Job 36:26-33, notes; Job 37:1-5, notes; and Psalm 29:1-11.
The skies sent out a sound - The voice of thunder, which seems to come from the sky.
Thine arrows also - The lightnings - compared with burning or ignited arrows. Such arrows were anciently used in war. They were bound round with rags, and dipped in some combustible substance - as turpentine - and shot into houses, grain-fields, haystacks, or towns, for the purpose of setting them on fire. It was not unnatural to compare the rapid lightnings with such blazing arrows.
Went abroad - They moved rapidly in all directions.

The clouds poured out water - It appears from this that there was a violent tempest at the time of the passage of the Red Sea. There was a violent storm of thunder, lightning, and rain. These three things are distinctly marked here.
1. "The skies sent out a sound:" the Thunder.
2. "Thine arrows went abroad:" the Lightning.
3. "The clouds poured out water:" the Rain. In the next verse we have,
4. An Earthquake: "The earth trembled and shook," Psalm 77:18.

The clouds poured out water: the skies sent out a (l) sound: thine arrows also went abroad.
(l) That is, thundered and lightninged.

The clouds poured out water,.... This, with some other circumstances which follow, are not related by Moses in the history of this affair; but as they are here recorded by an inspired penman, there is no doubt to be made of the truth of them; besides Josephus (a) relates the same things; he says, that at the time when the Egyptians were drowned in the Red sea, rains descended from heaven, and there were terrible thunders, lightnings, and thunderbolts; this was when the Lord looked through the cloud, and troubled the host of the Egyptians, Exodus 14:24,
the skies sent out a sound; or the airy clouds, the lighter ones, and which were higher in the heavens, as the others before mentioned were thick clouds, full of water, and hung lower; these were thunderclouds, and thunder is the sound which they sent forth, as in the following verse:
thine arrows also went abroad: that is, lightnings, as in Psalm 18:14, so Aben Ezra; but Kimchi interprets them of hailstones.
(a) Antiqu. l. 2. c. 16. sect. 3.

Poured - When the Israelites passed over the sea. Arrows - Hail - stones or lightnings.