1 Kings 20:9
Wherefore he said unto the messengers of Ben-hadad, Tell my lord the king, All that thou didst send for to thy servant at the first I will do: but this thing I may not do. And the messengers departed, and brought him word again. Wherefore he said unto the messengers of Ben-hadad, Tell my lord the king, All that thou didst send for to thy servant at the first I will do: but this thing I may not do. And the messengers departed, and brought him word again.
The verse stands within the history of Ben-hadad's wars against Israel. After an earlier siege of Samaria the Syrians fled and Ben-hadad himself escaped. In the following year Israel defeated the Syrians, and Ben-hadad was defeated and surrendered to Israel's king.
In the verse Ahab answers the messengers of Ben-hadad that all that was first demanded of him as a servant he will do, but the further demand he refuses. God gave Ahab victory over the Syrian king as another effort to win the weak Ahab. Ahab knew that the victory came from Jehovah, yet greater disobedience followed.