Charles Ellicott Commentary 1 Kings 20:36

"Then said he unto him, Because thou hast not obeyed the voice of Jehovah, 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." — 1 Kings 20:36 (ASV)

A lion shall slay you. —It is obvious to compare the example of 1 Kings 13:24.