Charles Spurgeon Commentary 1 Kings 20:18

"And he said, Whether they are come out for peace, take them alive, or whether they are come out for war, taken them alive." — 1 Kings 20:18 (ASV)

Whether they be come out for peace, take them alive; or whether they be come out for war, take them alive.

They were not to be so easily taken as Benhadad imagined.