I will be a lying spirit] I will so work on them, as they shall declare false things, John 8:44. Thus he is called, a spirit of whoredom, Hosea 4:13. meaning spirituall whoredom, which is idolatry: and an unclean spirit, Zac. 13. 2. and a spirit of errour, 1 John 4:6. because he allures men to those sins. he said] The LORD. Because Ahab hated Gods true prophets, God in justice gave him over to believe lies. See on 2 Thessalonians 2:11-12.