1 Kings 22:20

“ And YHWH said, ‘Who will entice Ahab, that he may go up and fall at Ramoth-gilead?' And one said on this manner, and another said on that manner.”

What Micaiah was trying to give here was an explanation of the prophesying of the false prophets, and he did it in striking picture terms. His aim, in other words, was to give an explanation of the ‘inspired' prophets that he saw before him in terms that all would understand and not forget. He was not really suggesting that YHWH actually behaved like this, or that these lying spirits actually appeared before YHWH. Indeed he wanted the people to realise that it was these prophets who were possessed by lying spirits and were thus not actually conveying YHWH's will at all. But trouble was that many of the people thought that they were. So Micaiah wanted them to recognise that what these prophets were speaking was lies.

1 Kings 22:21

‘ And there came forth a spirit, and stood before YHWH, and said, “I will entice him.” '

Here, Micaiah was saying, is the real source of the prophecies of the false prophets, a ‘spirit of prophecy' which sought to entice men into catastrophe, and granted permission to do so by YHWH. In a sense it could be seen as coming from YHWH because nothing could happen without YHWH's say-so. He was sovereign over all. Compare how even Satan could be described as a ‘son of the Elohim' in Job Chapter s 1 & 2. He too was permitted some rein by God (although always on a tight rein).