Albert Barnes Commentary Psalms 104:25

"Yonder is the sea, great and wide, Wherein are things creeping innumerable, Both small and great beasts." — Psalms 104:25 (ASV)

So is this great and wide sea ... — Our translation here does not quite express the beauty and the force of the original: “This sea! Great and broad of hands! There is the creeping thing—and there is no number; animals—the little with the great.” The reference here is undoubtedly to the Mediterranean Sea, which it is likely was in sight when the psalm was composed, as it is in sight not only along the coast but also from many of the elevations in Palestine.

The phrase “wide of hands,” applied to the sea, means that it seems to stretch out in all directions. Compare the notes at Isaiah 33:21. The “creeping things” refer to the variety of inhabitants of the deep that glide along as if they crept. See the notes at Psalms 104:20.

The word “beasts” refers to any of the inhabitants of the deep, and the idea is that there is an endless variety “there.” This reflection cannot help but impress itself on the mind of anyone when looking on the ocean: What a countless number, and what a vast variety of inhabitants are there in these waters—all created by God, all provided for by his bounty!