I find the story of Saul and the medium of En-dor intriguing and challenging. What kind of divination was done and how were the dead consulted in the ancient world?
The narrative recorded in 1 Samuel 28:3-19 is unique in the Bible, and consequently it is somewhat difficult to understand the details of the story clearly.
Saul was confronting a serious military crisis and, after unsuccessfully attempting to consult the Lord, decided to seek the guidance of a necromancer through whom he thought he could get God's counsel. This was an attempt to force God to speak, based on magical ideas that required the performance of certain ritual practices in order to be fully effective.
1. The necromancer is called "a woman who is a medium" (1 Sam. 28:7, NIV), that is to say, a woman who possessed a spirit. She apparently had the ability to communicate with the dead, seeking oracles from them. This type of persons were called "those who ask the spirits" (see Deut.18:11). Apparently they were possessed by the spirit they consulted, functioning as a medium. This is suggested by Lev. 20:27: "A man or a woman in whom there is a spirit. . ." (literal translation). In a sense this was a counterfeit of the gift of prophecy through which the prophet was possessed by the Spirit of the Lord, received messages from Him, and gave oracles to the people.
2. The Hebrew word translated "spirit" in this narrative is 'ob, and designates the necromancer ( I Sam. 28:3) as well as the spirit of the dead itself (Lev. 20:27), not ruah, which is the one used to refer to the Spirit of God. Its etymological meaning is not known, although it is believed by some that it may have meant "pit," or "hole on the ground."
Consulting the dead required that a hole be made in the ground in which food and blood were placed with the clear purpose of enticing the spirit to come up from the underworld to enjoy this offering. The underworld, according to this ancient mythology, was also where demons were located, and they too seemed to have enjoyed blood (cf. Lev. 17:7).
The ritual was performed at night, and Hittite mythology indicates that in some cases a small ladder was placed in the hole to facilitate the ascension of the spirit; at other times the necromancer placed himself or herself inside the hole in order to receive the message. Apparently the spirit spoke to or through the necromancer in undertones, whispering the oracle, chirping and muttering (Isa. 8:19).
3. The necromancer consulted by Saul did not really bring up Samuel. She simply had a visionary experience that no one else was able to see. She told Saul: "I see a divine being coming up out of the ground" ( verse 13, NRSV).
That the king was not able to see this being is clearly indicated by his question: "What is his appearance?" She then described the being she saw: "An old man. . . wrapped in a robe." Saul concluded, based on that description, that it was Samuel (verse 14, NRSV).
4. The spirit probably spoke to Saul through the medium and not directly and personally. As we indicated already, this was the way the oracle was communicated from the spirit to the person seeking counsel. Interestingly, the "divine being" did not say anything new to Saul. It simply repeated the message given by God through Samuel when he was still alive. In other words, it had no special knowledge inaccessible to human beings. The narrative rejects the common idea that the dead could function as guides for the living. Although those spiritual powers were called "the ones who have knowledge" (see Lev. 20:27), this story rejects that popular idea.
5. Who was it, then, who spoke to Saul through the medium? The narrative does not say. It tells only who the protagonist of the story believed him to be.
We must, therefore, examine the larger context of the story in the Bible. We know that the Lord condemned any attempt to communicate with the dead (Deut. 18:10, 11). We also know that the realm of death is where demonic powers are active (Heb. 2:14). In addition, we know that demons desire to communicate with humans, and at times they can possess them as their instruments (e.g., Acts 19:13-16). And finally, we are told that Satan can transform himself into what seems to be an angel of light to deceive humans (2 Cor. 11 :14).
Based on the overall teachings of the Bible we can conclude that it was not Samuel who spoke to Saul but some other spiritual power not from God.