en_tn/2ki/06/11.md

Will you not tell me who among us is for the king of Israel?

The king of Aram assumes there is a traitor among his soldiers who is giving information to the Israelite king. He uses this rhetorical question to try to find out who that traitor is. This can be written as a statement. Alternate translation: "Tell me which of you is for the king of Israel!" or "Tell me which of you is revealing our plans to the king of Israel!" (See: rc://en/ta/man/jit/figs-rquestion)

is for the king of Israel

"To be for someone" means to be loyal to that person. In this case, it means that they would give information to help the king of Israel. Alternate translation: "is helping the king of Israel" or "is loyal to the king of Israel" (See: rc://en/ta/man/jit/figs-idiom)