It can be stated clearly that the kings say this. Alternate translation: "The kings say to their armies, 'Dedicate yourselves" (See: [[rc://en/ta/man/translate/figs-explicit]])
The attacking army tries to ensure that their gods will help them during the war by performing ceremonies and making sacrifices to them. Alternate translation: "Prepare for war by purifying yourselves and sacrificing to the gods" (See: [[rc://en/ta/man/translate/figs-explicit]])
To arise or stand up is a metaphor for no longer watching and thinking and instead beginning to act. Alternate translation: "Let us stop thinking and begin to attack" (See: [[rc://en/ta/man/translate/figs-metaphor]])
The end of the day is spoken of in terms of its light becoming dark. Alternate translation: "the day is ending" or "it is beginning to get dark" (See: [[rc://en/ta/man/translate/figs-metonymy]])