Here the word "sword" represents soldiers who fought with swords. The phrase "fell by the sword" is an idiom that means to die in battle. AT: "Their priests died in battle" or "Enemies killed their priests with swords" (See: [[rc://en/ta/man/translate/figs-metonymy]] and [[rc://en/ta/man/translate/figs-idiom]])
The Lord not acting for a period of time is spoken of as if he were asleep, and his beginning to act is spoken of as if he awakened. AT: "the Lord began to act as if he had awakened from sleep" (See: [[rc://en/ta/man/translate/figs-metaphor]])
Possible meanings are 1) like a warrior who had drunk too much wine and has become angry because he was awakened and so wants to fight or 2) like a warrior who drank much wine but is now able to think and fight well because he has slept.