And he said, I will go out, and be a lying spirit in the mouth of all his prophets. And the Lord said, Thou shalt entice him, and thou shalt also prevail: go out, and do even so. (2 Chronicles 18:21)
The divine command in the parabolic vision represents divine permission. Satan desired to bring about the death of Ahab, and the Lord did not prevent him. As long as God’s restraining hand is stretched out, Satan is not permitted to kill, but when God’s hand is removed, then Satan goes forth in his work of death and destruction (see GC 614).