Then the prophet said to him, “Because you have not obeyed the voice of the LORD, as soon as you depart from me a lion will kill you.” And when he left, a lion found him and killed him.
Here is an account of what followed upon the victory which Israel obtained over the Syrians. I. Ben-hadad's tame and mean submission. Even in his inner chamber he feared, and would, if he could, flee further, though none pursued. His servants, seeing him and themselves reduced to the last extremity, advised that they should surrender at discretion, and make themselves prisoners and petitioners to Ahab for their lives, Kg1 20:31.
Commenting on 1 Kings 20:31-43
Then said he unto him, because thou hast not obeyed the voice of the Lord,.... In not smiting him; which, if he was a prophet, he must know how great an evil it was to disregard or disobey what was said by a prophet in his name; he must be inexcusable: behold, as soon as thou art departed from me, a lion shall slay thee.
Then said he unto him, Because thou hast not obeyed the voice of the LORD, behold, as soon as thou art departed from me, a lion shall slay thee. And as soon as he was departed from him, a lion found him, and slew him. (r) Because you have transgressed the commandment of the Lord.