He gathered together the waters of the sea as into a heap. [1] Here the Psalmist does not speak of all that might have been said of every part of the world, but under one department he comprehends all the rest. He celebrates, however, a signal and remarkable miracle which we see in looking on the surface of the earth; namely, that God gathers together the element of water, fluid and unstable as it is, into a solid heap, and holds it so at his pleasure. Natural philosophers confess, and experience openly proclaims, that the waters occupy a higher place than the earth. How is it then that, as they are fluid and naturally disposed to flow, they do not spread abroad and cover the earth, and how is it that the earth, which is lower in position, remains dry? In this we certainly perceive that God, who is ever attentive to the welfare of the human race, has inclosed the waters within certain invisible barriers, and keeps them shut up to this day; and the prophet elegantly declares that they stand still at God's commandment, as if they were a heap of firm and solid matter. Nor is it without design that the Holy Spirit, in various passages, adduces this proof of divine power, as in Jeremiah 5:22, and Job 38:8 In the second part of the verse, he seems to repeat the same idea, but with amplification. God not only confines the immense mass of waters in the seas, but also hides them, by a mysterious and incomprehensible power, in the very bowels of the earth. Whoever will compare the elements among themselves, will reckon it contrary to nature that the bottomless depths, or the immeasurable gulfs of waters, whose native tendency is rather to overwhelm the earth, should lie hid under it. That so many hollow channels and gulfs, accordingly, should not swallow up the earth every moment, affords another magnificent display of divine power; for although now and then some cities and fields are engulfed, yet the body of the earth is preserved in its place.

Footnotes

1 - In Genesis 1:9 we read, "God said, Let the waters under the heavens be gathered together into one place, and let the dry land appear: and it was so." The Psalmist here probably has a reference to that passage, as in the 9th verse there is evidently an imitation of the style in which God is described in the first chapter of Genesis as performing the work of creation.

He gathereth the waters of the sea together as an heap - The Hebrew word here rendered "gathereth" is a participle; "gathering." The design is to represent this as a continuous act; an act not merely of the original creation, but constantly occurring. The reference is to the power by which the waters are gathered and kept together; the continual power which prevents their overspreading the earth. The word rendered "heap" - נד nêd - means properly a heap or "mound," and is applied to the waves of the sea heaped up together like mounds. Compare Joshua 3:13, Joshua 3:16; Exodus 15:8 : Psalm 78:13. He collected those waters, and kept them in their places, as if they were solid matter. This denotes the absolute control which God has over the waters, and is thus a most striking illustration of his power.
He layeth up the depth in storehouses - The abysses; the deep waters; the masses of water. He places them where he pleases; he disposes of them as the farmer his grain, or the rich man his treasures. The caverns of the ocean - the ocean-beds - are thus vast reservoirs or treasure-houses for the reception of the waters which God has chosen to deposit there. All this is proof of his amazing power, and all this lays a proper foundation for praise. Occasions for gratitude to him may be found in every world that he has made; in every object that has come from his hand; and nothing more "obviously" suggests this than his wondrous power over the waters of the ocean - collecting them, restraining them, controlling them, as he pleases.

He gathereth the waters of the sea together - He separated the water from the earth and, while the latter was collected into continents, islands, mountains, hills, and valleys, the former was collected into one place, and called seas; and by his all-controlling power and providence the waters have been retained in their place, so that they have not returned to drown the earth: and he has so adapted the solar and sonar influence exerted on the waters, that the tides are only raised to certain heights, so that they cannot overflow the shores, nor become dissipated in the atmospheric regions. In this one economy there is a whole circle of science. The quantity of matter in the sun, moon, and in the earth, are all adjusted to each other in this astonishing provision: the course of the moon, and the diurnal and annual revolutions of the earth, are all concerned here; and so concerned, that it requires some of the nicest of the Newtonian calculations to ascertain the laws by which the whole is affected.

He (f) gathereth the waters of the sea together as an heap: he layeth up the depth in storehouses.
(f) By the creation of the heavens and beautiful ornament with the gathering also of the waters, he sets forth the power of God, that all creatures might fear him.

He gathereth the waters of the sea together as an heap,.... Which was done on the third day of the creation, by means of which the dry land appeared, Genesis 1:9; when the waters of the sea were piled up as an heap, and stood higher than the earth, as they now do; and which is a wonderful instance of the power and providence of God, to bound them, and preserve the earth from being overflowed by them, Job 38:9;
he layeth up the depth in storehouses; that is, large quantities of water, for which he has his treasure houses, as for the wind, hail and snow, Psalm 135:7; and these are the clouds of heaven above, and the fountains of the great deep below, which the Lord opens and stops at his pleasure; see Genesis 7:11.

Store - houses - Either in the clouds, or in the bowels of the earth.