John Gill Commentary 2 Kings 6:11

"And the heart of the king of Syria was sore troubled for this thing; and he called his servants, and said unto them, Will ye not show me which of us is for the king of Israel?" — 2 Kings 6:11 (ASV)

Therefore the heart of the king of Syria was sore troubled for this thing There was as it were a storm in his breast, as the word signifies; he was like a troubled sea, tossed with tempests, exceeding uneasy in his mind, fretting at the disappointment he met with time after time:

and he called his servants, and said to them, will you not show me which of us is for the king of Israel ? he suspected that some one of his counsellors was in the interest of the king of Israel, and betrayed his secrets to him, which was the cause of his disappointments.