What does 1 Kings 20:35 mean?

So they put sackcloth on their bodies and ropes on their heads, and came to the king of Israel, and said, “Your servant Ben Hadad says, ‘Please let me live.’” He said, “Is he still alive? He is my brother.”

Now the men observed diligently, and hurried to take this phrase; and they said, “Your brother Ben Hadad.” Then he said, “Go, bring him.” Then Ben Hadad came out to him; and he caused him to come up into the chariot.

Ben Hadad said to him, “The cities which my father took from your father I will restore. You shall make streets for yourself in Damascus, as my father made in Samaria.” “I”, said Ahab, “will let you go with this covenant.” So he made a covenant with him, and let him go.

Then he said to him, “Because you have not obeyed Yahweh’s voice, behold, as soon as you have departed from me, a lion will kill you.” As soon as he had departed from him, a lion found him and killed him.

Then he found another man, and said, “Please strike me.” The man struck him and wounded him.

So the prophet departed, and waited for the king by the way, and disguised himself with his headband over his eyes.