from sea to sea: This phrase represents the entire world.
Solomon's kingdom stretched from the Euphrates River in the east to the Philistine territory in the west (1 Kings 4:21; see Psalms 80:8–11; 89:19–25), where the Mediterranean Sea appeared to be at the ends of the earth (see 2:8).
Everyone will bow before this king, including desert nomads (Psalm 72:9), his enemies, and all the world's kings (see Micah 7:17).