Question: It is obvious that she is permitted immediately, as once he dies the condition is as if it is fulfilled, as he certainly will not return to his house! (What is the Gemara's question?)

Answer: Even so, they still need to ask whether or not we decree that in a case where he died the law is that she is not permitted immediately, due to a case where he did not yet die. (The Avodah Berurah cites Tosfos in Gitin 76b, DH "d'Ha" as explaining that we do not want to permit her immediately as it is not yet known that he died, and people will start saying how she was permitted anyway. It is therefore better to wait the full twelve months.)

Explanation: This refers to the people of his generation who argued on him.

Implied Question: However, one cannot deduce from here that the law is unlike Rebbi Yosi. (Why not?)

Answer: This is because our Gemara is only saying that they do not agree with him when this condition is made orally. However, if it is made in a document, they admit to Rebbi Yosi.

Question: This is difficult. We say in Chulin (66a) that the house of Rebbi Yishmael taught that in a case where the grasshopper has a long head, it is permitted. The Mishnah there as well implies that if it has a long head it is permitted, as the Mishnah did not state amongst the signs of a kosher grasshopper that it must not have a long head.

Question (cont.): In Shabbos (90b), the Gemara says that a Shushiva is permitted, as Rav saw Rav Kahana passing a Shushiva by his lips. Rav said to him, take it away, as you might eat it while it is still alive, thereby transgressing Bal Tishaktzu! This implies it would only have been prohibited to eat it while it was alive, not when it was dead. (All of these sources contradict our Gemara's statement that it is clearly forbidden if it has a long head!)

Answer: It therefore appears to Rabeinu Tam that the text should read in our Gemara that if it has a long head, everyone agrees it is permitted. This text is indeed found in the commentary of Rabeinu Chananel.

Explanation: The case is where Reuven touched a dead person, and Shimon came along and touched Reuven while he was still touching the dead person. Impurity of connection is certainly a Torah law.

Implied Question: When Rava said, "Do not hang empty bottles (i.e. statements empty of reason) on Rav Nachman" it was not because he held that impurity through connection is not a Torah law. (What, then, did he mean?)

Answer: Rather, it was because Rava merely held that Yosef ben Yoezer (37a) was not discussing this topic. This is also implied in Nazir (42b, and Tosfos there, DH "b'Chiburi").

Implied Question: This does not really mean that it is learned from Sotah, as if there is a doubtful situation of impurity in the public domain in which there is a status quo that something is pure, we do not require a teaching from Sotah to teach that it remains pure. Rather, we say that the status of the item should be maintained, and we do not have to derive from Sotah. (What does the Gemara mean when it says we derive this from Sotah?)

Explanation (cont.): Rather, it is referring to the fact that a doubt in the private domain is ruled impure, as the case of Sotah is also a doubt of impurity (i.e. married woman having an affair) in the private domain (i.e. seclusion).

Opinion: Rabeinu Tam says that being that the Gemara asks about the source for the prohibition of Shelakos (see definition below), implying it is a Torah law, perhaps it is an early decree which was not decreed at the same time as bread (but rather earlier).

Opinion (cont.): Shelakos (here) refers to cooked dishes, as implied in our Gemara. Originally they made this decree due to intermarriage, but did not make a similar decree regarding bread because there is not a strong suspicion it will lead to intermarriage. This was until Shamai and Hillel decreed this should be forbidden as one of the (famous) eighteen things.

Implied Question: This is despite the fact that in our Mishnah bread is stated before Shelakos. (Doesn't this imply bread is an earlier decree?)

Answer: Even so, Shelakos is in fact an earlier decree. When they permitted bread they did not permit Shelakos, being that these are two different decrees.

Opinion#1: Rabeinu Tam says that one must make an Eiruv Tavshilin with bread and a cooked dish.

Proof: He brings proof to this from the Gemara in Beitzah (15b) where Rebbi Eliezer says that one can only bake based on something baked, and one can only cook based on something cooked. This is as the Pasuk says, "That which you bake, bake, and that which you cook, cook." This is also the opinion of the Bahag.

Opinion#2: However, the Ri says that it is enough to have either bread or a cooked dish for Eiruv Tavshilin. We do not rule like the statement of Rebbi Eliezer in Beitzah (ibid.), as he is from Beis Shamai. He is also following the opinion of Chananyah according to Beis Shamai that one needs bread, a cooked dish, and a hot dish that is insulated (to be kept hot, if one wants to insulate things on Yom Tov). Beis Hillel permits all of these actions (cooking, baking, and insulating etc.) by making an Eiruv Tavshilin comprised of one cooked dish. (See Beitzah 17b for the Beraisa with the argument between Beis Shamai and Beis Hillel.)

Opinion#2 (cont.): In the Yerushalmi in Beitzah, Rebbi Yehoshua clearly argues on Rebbi Eliezer's opinion. The Yerushalmi there quotes the Pasuk, "That which you will bake, bake, and that which you will cook, cook." The Yerushalmi continues that Rebbi Eliezer says that one can bake based on that which was baked, and one can cook based on that which was cooked. Rebbi Yehoshua says that one can bake and cooked based on something that was cooked. We say that in a Rabbinic argument one should follow the lenient opinion, and here Rebbi Yehoshua is the lenient opinion.

Opinion#2 (cont.): Additionally, in our Gemara n Beitzah (17b), we see that Chananyah quotes Beis Hillel as only requiring one cooked dish.

Observation: However, the custom has become to use bread and a cooked dish, being that it is the opinion of the Bahag and Rabeinu Tam. [See also Tosfos in Beitzah 17b, DH "Amar Rava."]