Here "blood" refers to the blood of the people of Sidon and represents those whom their enemies would kill. (See: [[rc://en/ta/man/translate/figs-metaphor]])
Here "the slain" means the people of Sidon whom their enemies would kill. Alternate translation: "the slain people will fall" (See: [[rc://en/ta/man/translate/figs-nominaladj]])
Here "sword" is a metonym for an attacking enemy army. Alternate translation: "When enemy armies attack you" (See: [[rc://en/ta/man/translate/figs-metonymy]])