Here it says that Adah bas Eilon was the name of Esav's wife. Why does it refer to her above (26:34) as 'Bosmas' bas Eilon?
Rashi: Because she burned Besamim (incense) to Avodah Zarah.
Ramban: They were not the same person; refer to 36:3:1:4.
Here it says that Esav's other Kena'ani wife (not from Eilon) was called Aholivamah bas Anah. Why does the Pasuk above (26:34) refer to a wife named "Yehudis bas Be'eri"?
Rashi: Esav called her Yehudis, to trick Yitzchak into believing that she denied Avodah Zarah. 1
Rashbam: Yehudis bas Be'eri died without children. 2 After Esav moved to Har Se'ir, he married into the Chori, i.e. Aholivamah bas Anah bas Tziv'on ben Se'ir ha'Chori. Also Timna, Elifaz' concubine, was from Bnei Se'ir. Since Aholivamah was Esav's last wife, she and her sons are mentioned last. 3
Ha'amek Davar: Yehudis died without sons. After Esav married Bosmas, he married Aholivamah before he went to Har Se'ir. She is mentioned (without her sons) before Bosmas, to list his Kena'ani wives together. Her sons are listed last, since she was his last wife.
Anah was Tziv'on's son, not his daughter (as recorded later, in 36:24). In any event, how can Aholivamah have been the daughter of both Anah and Tziv'on?
Rashi: Because Aholivamah was the product of the illicit relationship between Tziv'on and Anah's wife (i.e. his daughter-in-law), in which case she was the daughter of Tziv'on and of Anah's wife. 1
Ha'amek Davar: Refer to 36:24:153:1.
Hadar Zekenim: Aholivamah was Tziv'on's granddaughter. A granddaughter can be called a daughter. 2
Moshav Zekenim (to 36:14); Ramban (to 36:24), from Pesachim 54a: Anah had Bi'ah with his mother, and Aholivamah was born. 3
Moshav Zekenim (to 36:14, from Bava Basra 115b): Anah was a female. 4 Tziv'on fathered her through his own mother. Anah is listed among heirs of Se'ir, for she inherited in place of her father Tziv'on, who had died. It says "Hu Anah" (masculine) because she inherited like a son. 5
Midrash Tanchuma (Vayeshev 1): Anah's wife had Bi'ah with Anah and Tzivon, and Aholivamah was conceived from both of them. Radak (to Shmuel I 17:23) - this is like the opinion that a woman can conceive one child from many men. Some expound similarly about Golyas.
This teaches us that Esav's family was riddled with Mamzerus (also see 36:12:2:3 and the note there). Moshav Zekenim (to 36:24), Gur Aryeh - She is called Bas Anah because people assumed that she is Anah's daughter. (The Ramban to 36:25 cites this explanation in the name of the Midrash, but concludes that it does not fit well into the Pasuk.)
Mizrachi: This is difficult. There was no other Anah, so there is no need to specify Anah's father! (It seems that Moshav Zekenim (to 36:14) learns from Bechor Shor that she is called Bas Tziv'on because she inherited in place of her grandfather Tziv'on. I.e. there were no living sons or grandsons of Tziv'on - Dishan (36:26) is Se'ir's son (36:21), and not Anah's son, and the brother and son of Anah (Dishan and Ayah) died without children. (PF). Gur Aryeh - if the Torah wanted to name her grandfather, it should have said 'bas Anah ben Tziv'on. Rather, it says 'bas Tziv'on' for she was his daughter. Refer to 36:2:3.3 and 36:2:3.1:1.
Ramban: She is called Bas Tziv'on, for people assumed that she is Tziv'on's daughter. (Note that this is the reverse of Rashi's explanation.)
Gur Aryeh: This is difficult. Refer to 36:2:3.1:1.
Moshav Zekenim: Anah had a brother Ayah. Ayah should have inherited, and not her! We must say that Ayah died without children. The Torah does not list children from him.
QUESTIONS ON RASHI
Rashi writes: "Bas Anah, Bas Tziv'on - [How can she be both?]" But perhaps it means that Aholivamah's mother was named Anah, the daughter of Tziv'on?
Gur Aryeh: The Torah does not write the mother's lineage in place of the father's, unless it is for a specific reason. 1 We also do not know of a woman named Anah, only a man (in 36:20,24).
But see Moshav Zekenim to 26:34; refer to 26:34:151:1*.
Rashi writes: "This teaches that Tziv'on lay with his daughter-in-law, the wife of Anah, and Aholivamah came about from among the two of them." But perhaps it was the reverse; that Anah had lain with the wife of his father Tziv'on, and Anah was the true father?
Mizrachi: It is more plausible to say that it was one person, Tziv'on, who committed incest twice. (See Rashi to 36:24, that Tziv'on had previously lain with his mother, fathering Anah.)
Gur Aryeh: If Anah was the true father of Aholivamah, once the Torah calls her the daughter of Anah, it would not then qualify this by also attributing her to her supposed father Tziv'on. Rather, Tziv'on was the true father. 1
Gur Aryeh: This also explains why Rashi to 36:24 doesn't reverse the blame in that case as well. Anah's true father was the second one mentioned (Tziv'on), and the supposed father was the first one (Se'ir).
Rashi writes: "'Bas Anah, Bas Tziv'on' - ... Tziv'on lay with his daughter-in-law...and Aholivamah came about from among the two of them." Why don't we simply say that Tziv'on was her grandfather, and that grandchildren are like children (Yevamos 62b; also see Rashi to Bereishis 20:12, and to Shemos 28:1)?
Gur Aryeh #1: If so, the Torah would have written 'Aholivamah, daughter of Anah, son of Tziv'on.'
Gur Aryeh #2: When explaining the lineage of a family tree, one should not use this rule, but rather attribute each child to his father specifically. See Rashbam to Bava Basra 115b.
Rashi writes that Aholivamah bas Anah bas Tziv'on ha'Chivi, is one and the same as Yehudis bas Be'eri ha'Chiti. But Chivi and Chiti are different nations! And below, Tziv'on is listed among "Bnei Se'ir ha'Chori." Chori is another nation!
Moshav Zekenim, citing R. Yitzchak: Really, [Tziv'on] is a full Chiti. He is called Chivi and Chori for a Derashah (Shabbos 85a - they knew what is good to plant in each location. Chori were Meri'ach (smelled) the earth. Chivi would taste the land like a Chivya (a snake that eats earth.) This forced the Gemara to expound these names more than other names of nations.)
Mizrachi: A Chivi and a Chiti had Bi'ah with Tziv'on's mother, therefore he is attributed to both of them.
Gur Aryeh: The Chivi were the worst of the descendants of Cham. (Chivya means 'snake' in Aramaic; that nation was accursed like the snake of Bereishis.) Just like Esav lied about her father's name (refer to 36:2:153:1), he lied about her nation. 1
Rashi writes that Adah was her real name; she is called Bosmas due to her idolatry. Why does Rashi say (Rashi to 36:3) regarding Esav's third wife, that Bosmas [bas Yishmael] was her real name, and she is called Machalas for another reason?
Gur Aryeh (to 36:3): The Torah calls her Machalas at the time that Esav married her, to teach that one who marries gets Mechilah (pardon). Refer to 36:3:1.2:1 and the notes there.
Rashi writes that Esav called Aholivamah bas Anah, 'Yehudis,' to feign that she denied idolatry. But in 26:34, her father's name is Be'eri, while in this Pasuk it is Anah / Tziv'on! Why would Esav change her father's name as well?
Gur Aryeh: Aholivamah's [supposed] father Anah was known to himself be illegitimate (Rashi to 36:24). Esav therefore referred to her by a completely different name, Yehudis Bas Be'eri, to hide her lineage from his father Yitzchak.
Rashi writes that Esav called Aholivamah 'Yehudis' to feign that she denied idolatry. Why didn't he also change Adah's name to trick Yitzchak?
Sifsei Chachamim: Indeed, he changed her name as well. The Torah called her "Bosmas" (26:34) to hint to why Yitzchak's eyes grew weak (from the incense).
Rashi writes that Adah was Bosmas; and Aholivamah is Yehudis. Why did the Torah change the order of Esav's first two wives?
Perhaps Esav put Adah first because she already bore a son to him, and Aholivamah did not (refer to 36:2:156:1). (PF)
Rashi writes that Aholivamah is Yehudis. If so, why does the Torah list the sons of his third (last) wife (Bosmas bas Yishmael) after the sons of Adah, and before the sons of Aholivamah? It does so three times - in verses 36:4-5, 10-14, 15-18! (Ha'amek Davar)
Perhaps Bosmas' son is listed before Aholivamah's sons, for he was born before them. 1 (PF) Ha'amek Davar -Aholivamah's sons did not have sons when Esav went to Har Se'ir, but Esav's other sons did; this suggests that Aholivamah's sons were younger. 2
Perhaps the Torah first lists the sons of Adah and Bosmas, for each had only one, before the three sons of Aholivamah. Tana'im taught first matters with few laws, before matters with many laws (Shevu'os 3a, Bechoros 13a). 3 (PF)
If so, (based on Megilah 17a), Aholivamah was married at least 23 years before she bore sons; perhaps she bore daughters before this. (PF)
Ha'amek Davar rejected Rashi based on this question. He said that Aholivamah's sons were younger to support that she is not Yehudis, and Esav married her after Bosmas. (PF)
However, in Nedarim (2b), the Tana taught first matters with many laws! And I do not know a source that the Torah teaches first the more concise matter. (PF)