The phrase "knowledge of Yahweh" represents people who know Yahweh. Alternate translation: "the earth will be full of those who know Yahweh" or "those who know Yahweh will cover the earth" (See: [[rc://en/ta/man/translate/figs-metonymy]])
This phrase is used to show how full the earth will be of people who know Yahweh. It may be clearer that it does this if its words are similar to the words in the previous phrase. Alternate translation: "as the seas are full of water" (See: [[rc://en/ta/man/translate/figs-simile]])