Wherefore he said unto the messengers of Benhadad, 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.
So, he told Benhadad's messengers to say to their king, "I will do everything you asked for initially, but I can't do this extra thing." The messengers left and reported back to him.