Which Lav forbids Ba'al Ov? "Al Tifnu El ha'Ovos."

What is the source for Kares? "Veha'Nefesh Asher Tifneh El ha'Ovos v'El ha'Yid'onim..."

What is the source for punishment? "Ish Oh Ishah Asher Yihyeh Vahem Ov Oh Yid'oni Mos Yumasu."

Question: Why wasn't Yid'oni taught in [the first Mishnah of] Kerisus (which lists all the Aveiros of Kares)?

Answer #1 (R. Chizkiyah citing Reish Lakish): It is because all of them (i.e. both Ov and Yid'oni) were included in one Lav - "Al Tifnu El ha'Ovos..." (Therefore, one who transgresses both in one Helam brings only one Chatas.)

Answer #2 (R. Yosa citing Reish Lakish): It is forbidden only due to a Lav that comes from the power of an Aseh. (I.e. it is a Lav she'Ein Bo Ma'aseh (GILYON EFRAYIM). One never brings a Korban for it - KORBAN HA'EDAH.)

Objection (R. Yosa, to Chizkiyah): Why does no one teach Yid'oni among Kerisus, only you?! (According to you, one is Chayav Korban for it, just like for Ov. Why is it never taught among Kerisus?)

Answer (Chizkiyah): Just like Torah teaches [Ov first], the Mishnah teaches [Ov - GILYON EFRAYIM] (and then it cannot teach Yid'oni, for this would imply that one is liable for both of them in one Helam).

Ov or Yid'oni - Ov is a witch who [conjures up a Mes, and it] speaks under his armpit. Yid'oni is one who talks with his mouth. Both of these are stoned. One who asks (either of them to conjure up the dead) transgresses a Lav.

"V'Doresh El ha'Mesim" - some teach that this is one who asks a skull [through witchcraft], and some teach that this is one who raises [a Mes] bi'Zechuro on his Ever. (Doresh El ha'Mesim explains Ov and Yid'oni. Rashi says that 'Zechuro' is his penis; Tosfos holds that it is a kind of witchcraft.)

Question: What is the difference between one who asks a skull, and one who conjures up bi'Zechuro?

Answer: One who asks a skull, [the Mes] rises normally (the head is above), and he can rise on Shabbos, and a commoner can raise a king. One who conjures up bi'Zechuro, it does not rise normally (rather, upside down), and he cannot raise on Shabbos, and a commoner cannot raise a king.

(Rav Huna): A verse supports the one who says that Ov is one who conjures up bi'Zechuro. How do we learn this? [Sha'ul asked the Ba'alas Ov] "Kismi Na Li b'Ov v'Ha'ali Na Asher Omar Elayich." (This implies that the Mes rises, as opposed to one who asks a skull.)

Question: How do you learn from this?! (The Mes rises also when one asks a skull, like we said "it rises normally..."!)

Answer (R. Mana): It is because she knew many matters. (How did she deduce that Sha'ul asked her? We must say that she raised bi'Zechuro, and was shocked that Shmuel rose normally, and she concluded that it is due to the honor of Sha'ul.)

The words of Rabanan (Reish Lakish above, who said that Ov was taught in Kerisus, but not Yid'oni, for only Ov is Chayav Korban) support R. Yosa. R. Yosa said in the name of Rabanan that it is because [Ba'alei Ov do an action; they] offer Ketores to demons.

(R. Heila citing R. Yosa): [Only Ov was taught] because all of them were included in one Lav (so one who transgresses both in one Helam is liable only once. We explained the Sugya like KORBAN HA'EDAH.)