The story of the witch of En-dor in I Samuel 28 is obscure and seems rather strange. The Torah prohibits communication with the dead and yet Saul does just that.
“So Saul disguised himself, dressed in other clothes, and he and two men went and came to the woman at night.”
It is well known that mediums prefer to work at night since the darkness hides their schemes in which they use to trick their clients. Thus I argue here that the rising of Samuel was a trick by the witch.
However, some Jews feel that the Torah prohibits magic, necromancy, idolatry, and witchcraft because they work. I even once heard a rabbi say that were the prohibition of talking to the dead only a fable the Torah would not have prohibited it.
Ibn Ezra would disagree. Writing in his commentary to Leviticus, 19:31, he writes: "Those with empty brains say 'Were it not that fortune tellers and magicians were true, the Torah would not prohibit them.' But I (Ibn Ezra) say just the opposite of their words, because the Torah doesn't prohibit that which is true, but it prohibits that which is false. And the proof is the prohibition on idols and statues."
Additional sources who accepted the idea that witchcraft works were some talmudic rabbis (BT Sanhedrin 65a). Rashi, Radak, Altschuler, and Malbim accepted the Talmudic view. Saadiah, Hai Gaon, and Nachmanides felt that witchcraft does not always works, only on special occasions or when G-d allows.
Yet others, such as the rationalist Jews, such as Maimonides, ibn Ezra, Gersonides, and Samuel ben Hofni Gaon contend that the witch tricked Saul by pretending to be rising Samuel out of the dead. They support their view with Saul's question of a description of what she saw (verse 13); he saw nothing and blindly accepted what she told him.
If we accept the rational view that this was a trick then it would seem that part of her trick was to show her power in that she not only raised Samuel from the dead but recognized Saul in his new clothes. On the other hand, Saul did not see the Samuel. This is further evidence that she was tricking Saul. From this reading, we see that she did nothing. Radak writes that she knew who Saul was and that she was aware that he was seeking aid, specifically from Samuel.
Furthermore, it is significant that Samuel allegedly rose out of the earth, not from heaven (above) as would be excepted. Even more significant is the fact that Samuel does not rebuke Saul for using divination. Further evidence that the witch was tricking him. For if it was really Samuel, he would be aware of Torah laws. For example, I Chronicles 10:13 recounts that Saul paid for his transgressions when violating Leviticus 20:27 (which states that they should be killed) and Deuteronomy 18:11 (which considers it an abomination, we are commanded to drive them off the land).
Since it was a trick it follows that it was not a prophecy from Samuel, since this was not Samuel but a trick. Already showing signs of weakness and insecurity, and dwelling in a daydream: “Saul saw the Philistine camp, he was greatly afraid and his heart trembled greatly.” (Samuel I, 28:5) Realizing that his next activity was war, Saul sought aid from useless idolatry. When he turned to fantasy and imagination, he began to see forces that did not exist. His insecure mind failed him in battle which led to his ultimate death.