Albert Barnes Commentary 1 Kings 13:18

"And he said unto him, I also am a prophet as thou art; and an angel spake unto me by the word of Jehovah, saying, Bring him back with thee into thy house, that he may eat bread and drink water. [But] he lied unto him." — 1 Kings 13:18 (ASV)

But he lied to him - It is always to be remembered that the prophetic gift might coexist with various degrees of moral imperfection in the person possessing it. Note especially the case of Balaam.