O God, why. The first eleven verses of this psalm, like the first sixteen verses of Asaph's Psalm 73, constitute a lamentation about the apparent prosperity of God's enemies and His apparent indifference to the sufferings of His people. In both cases, the theme then changes to one of understanding and victory.

my King of old. The psalmist remembers that “the Lord sitteth upon the flood (Hebrew mabbul, the great cataclysm in Noah's day); yea, the Lord sitteth King for ever” (Psalm 29:10).

divide the sea. Psalm 74:13-17 is best understood as a commentary on Psalm 74:12: “For God is my king of old, working salvation in the midst of the earth.” The psalmist vividly recalls the ancient judgment of the great Flood, as assurance that He will eventually bring righteousness and peace out of sin and turmoil in this present world as well.

dragons in the waters. The mighty “dragons” in the waters, the same as “leviathan” (see also Job 41:1-34; Isaiah 27:1), were invulnerable to human weapons and were probably great marine reptiles, like dinosaurs. These “dragons” were broken and buried in the mighty waters and rushing sediments of the flood.

meat to the people. The “people” mentioned here could refer to the fish and other marine creatures whose habitats were overwhelmed in the Flood, but that were not preserved on the ark (which contained only land animals). The Hebrew word normally refers to human tribes, but can also be used for animal flocks (e.g., Proverbs 30:25). The carcasses of the mighty leviathans could have provided sustenance to sustain marine life through the cataclysm.

cleave the fountain. This must refer to the breaking open of all “the fountains of the great deep” (Genesis 7:11) at the beginning of the Food.

mighty rivers. The great flood-rivers, which drained the waters off the rising lands after the Flood, were gradually dried up, leaving their evidences in the great valleys and alluvia of all the earth's rivers. Almost all present-day rivers give evidence of much greater depths and flows in the past.

the light and the sun. Note that the “light” prepared by God is distinct from “the sun.” God first called for light energy, then light generators (Genesis 1:5, 14).

borders of the earth. God established both the boundaries of the lands and of the nations to occupy those lands, and even the inclination of the earth's axis to control their seasons.