What is "Bas Edom"?
Rav Sadya Gaon: The congregation of Edom.
Bavel destroyed Bayis Rishon. Why does our verse discuss Edom?
Rashi: Yirmeyah prophesized about Churban Bayis Sheni, which Romi destroyed.
Ibn Ezra: Edom was [subjugated] under Yehudah. They rejoiced on the day of Yehudah's fall. We find "Zechor Hashem li'Vnei Edom Es Yom Yerushalayim" - they told the Bavliyim "Aru Aru Ad ha'Yesod Bah" (Tehilim 137:7).
Why should they rejoice?
Rashi: They will rejoice temporarily. In the end, the cup of punishments will come on them. Ibn Ezra - this is like "Semach Bachur b'Yaldusecha" (Koheles 11:9) - in the end you will be judged. Ri Kara: This is like one who sees his colleague transgress, and says 'do all the sins that come to you, but know that Elokim will judge you for all of them.' Palgei Mayim - we find commands written in present tense, e.g. "u'Re'e Anyi" (Iyov 10:15).
Where is "Utz"?
Eichah Rabah 4:26: Bas Edom is Kisari in Eretz Utz, i.e. Romi.
Bava Basra 15a: Iyov (who lived in Eretz Utz - Iyov 1:1) died in Eretz Yisrael just before the Meraglim came 1 .
Ibn Ezra: This appears twice [in Tanach - here, and at the beginning of Sefer Iyov]. They are Aramim 2 .
It could be that after his afflictions in Eretz Utz, he moved to Eretz Yisrael. Mo'ed Katan 25a implies that normally] Nevu'ah is [only in Eretz Yisrael, but] not in Bavel. If so, presumably, Utz is in Eretz Yisrael. This applies also to the other opinions in Bava Basra, that Iyov was Jewish! (PF)
Bereishis 10:23: Utz was the son of Aram. Magihah (in Toras Chayim) - at the start of Iyov, Ibn Ezra proves that Iyov was from Esav! Perhaps the text here should say 'Edomim'.
Why does it say "Gam Alayich Ta'avar Kos"?
Ri Kara: The cup of punishments that came on Yisrael will come also on You.
What is the meaning of "[Tishkeri] v'Sis'ari"?
Rav Sadya Gaon: Your Ervah will be revealed. Ibn Ezra - this is like "va'Yiskar va'Yisgal" (Bereishis 9:21)
Rashi: You will get drunk and vomit. Tis'ari is like "va'Te'ar Kadah" (Bereishis 24:20).
Ri Kara: You will drink it and suck out [the last drop], and totally empty the cup. Woe to the nations that did not yet taste the cup of His anger, and will drink it later! Happy are Yisrael who already drank the cup of His anger, and will not drink it again (Yeshayah 51:22)!
Palgei Mayim (22): When you will get drunk from the cup of punishments that will come upon you, you will reveal to all the heresy hidden in your hearts. Refer to 4:22:3:2.
