EN ES
The Laws › Commandment #345
Commandment #345 · Negative · Occult Prohibitions · Necromancy

Do Not Consult the Yidoni (Familiar Spirit)

לֹא לְדָרְשׁ
Source: Leviticus 19:31  ·  Maimonides, Sefer HaMitzvot, Negative #594
אַל תִּפְנוּ אֶל הָאֹבֹת וְאֶל הַיִּדְּעֹנִים אַל תְּבַקְשׁוּ לְטָמְאָה בָהֶם אֲנִי יְהוָה אֱלֹהֵיכֶם
“Regard not them that have familiar spirits, neither seek after wizards, to be defiled by them: I am the LORD your God.”

Ov and Yidoni — Two Distinct Categories

Leviticus 19:31 pairs the Ov and the Yidoni in a single verse as the paradigmatic form of forbidden spirit-consultation. The two categories appear together five times in the Torah and the Nevi'im, always paired, always prohibited together. This consistent pairing suggests the Torah intends them as two poles of a single category — together they cover the full range of practitioners who claim to access hidden knowledge through unauthorized spiritual channels.

The distinction between them is methodological. The Talmud (Sanhedrin 65b) describes the Yidoni as operating through the bone of a specific bird placed in the mouth, using it as a medium through which the practitioner speaks words claimed to convey hidden knowledge. Where the Ov claims to channel the dead specifically (necromancy), the Yidoni claims a different form of occult knowledge — the root y-d-a (to know) suggests a practitioner of hidden knowing. The Torah prohibits both because the method — unauthorized access to spiritual knowledge — is the same, whatever the specific technique.

Josiah's Reform and the Eradication of the Yidoni

2 Kings 23:24: “Moreover the workers with familiar spirits (Ovot), and the wizards (Yideonim), and the images, and the idols, and all the abominations that were spied in the land of Judah and in Jerusalem, did Josiah put away, that he might perform the words of the law which were written in the book that Hilkiah the priest found in the house of the LORD.” Josiah’s reform is one of the most detailed acts of religious restoration in the Nevi'im. The Ov and Yidoni practitioners are listed alongside images and idols — not as a minor afterthought but as a core category of abomination requiring elimination.

The specific note that this purge was grounded in “the words of the law which were written in the book” — the recovered scroll of Deuteronomy — makes Josiah's reform a direct application of Torah law to national life. Deuteronomy 18:11 explicitly includes the Ov and Yidoni in its list of prohibited occult practices. Josiah identified what the text required and acted on it. His is the cleanest example in the Nevi'im of a king reading the Torah and systematically implementing its prohibitions.

“To Be Defiled By Them” — The Spiritual Cost of Consulting

Leviticus 19:31 does not prohibit the Ov and Yidoni because they are frauds. It prohibits consulting them because the act of seeking them out produces a specific spiritual effect: defilement (tum'ah). Leviticus 20:6 amplifies this: “And the soul that turneth after such as have familiar spirits, and after wizards, to go a whoring after them, I will even set my face against that soul, and will cut him off from among his people.” The consequence is severe: God turns his face away.

The language “to go a whoring after them” (liznot achareihem) is the Torah’s most intense language for covenant betrayal — the same language used for idolatry. Consulting the Yidoni is not categorized as mere superstition but as covenant adultery. The practitioner is a competing spiritual authority; consulting them is an act of infidelity toward the God of Israel. This framing — spiritual adultery — explains why the prohibition carries the specific response it does: God’s face turning away. The covenant relationship requires exclusivity; seeking another “knower” violates that exclusivity at the most fundamental level.

For reflection and group study
The Torah consistently pairs the Ov and Yidoni — in five separate passages across Leviticus, Deuteronomy, and Samuel. What does this consistent pairing reveal about how the Torah thinks about categories of forbidden practice? Is the pairing a literary device, a legal strategy (covering all possible forms), or a theological claim that these two practices together exhaust a specific category of spiritual transgression?
Josiah’s reform eliminated the Ov and Yidoni practitioners, purged the Temple, restored Passover, and removed idols — and yet 2 Kings 23:26 notes that “the LORD turned not from the fierceness of his great wrath, wherewith his anger was kindled against Judah.” Manasseh’s earlier sins, including his use of Ov and Yidoni, had set consequences in motion that Josiah’s reform did not erase. What does this reveal about the relationship between genuine repentance/reform and the consequences that have already been set in motion? Does the Torah's framework allow for consequences that repentance cannot reverse?

Read the source passage in the Torah reader.

Read in the Torah Reader — Leviticus 19:31