Observation: The Gemara in Nidah (70b) gives the same answer.

Implied Question: The Gemara could have given the answer given by the Gemara in Berachos (20b) that although Hash-m does not normally favor certain people, how can He not favor Bnei Yisrael who despite being commanded to say Birkas ha'Mazon only if they are satiated (from bread), insist on saying Birkas ha'Mazon even if they eat only one k'Zayis or k'Beitzah of bread? (Why didn't our Gemara give this answer?)

Answer: However, the answer in our Gemara is also a valid answer, that Hash-m only favors Bnei Yisrael before he makes a decree. (There is no preference in which answer should be given, as both are valid.)

Opinion: The correct text of our Gemara is Rabah, as Abaye's contemporary, Rava, was not a Kohen (see Chulin 133a). Our Gemara is referring to Rabah the contemporary of Rav Chisda.

Proof: This is clear from Rava's statement in Moed Katan (28a), that years of life, children, and one's livelihood is not dependent on merit but rather on "Mazal." Rava there continues that this is apparent, as Rabah and Rav Chisda were both completely righteous and were therefore able to bring rain through their prayers (in times where rain was needed), yet Rabah only lived for forty years while Rav Chisda lived for ninety-two years.

Question: How did Rava know that Rabah died early due to bad "Mazal?" Perhaps it was because he was descended from the House of Eli?

Answer: Even so, were it not for his bad Mazal the great merit of his Torah learning would have lengthened his life.

Question: Our Gemara implies that Rabah did not have the merit of doing Chesed. However, the Gemara in Sanhedrin (98b) says that Abaye told Rabah he has the merit of both Torah and Chesed!

Answer: Abaye did more Chesed than Rabah.

Observation: They did not send messengers for the month of Sivan to inform people when Shevuos was because this was dependent on when the Omer was brought.

Proof: This is as the Gemara stated earlier that Rav Shamayah taught that sometimes Shevuos is on the fifth (of Sivan), sometimes it is on the sixth, and sometimes it is on the seventh (depending on whether Iyar and Sivan were Chaser or Malei in the days when this was determined by witnesses).

Explanation: They inform them when Elul started, and they make Rosh Hashanah on the thirtieth day of Elul and the following day outside Eretz Yisrael.

Proof: This is as implied in Beitzah (5a) an Eruvin (39a) that they used to make two days of Rosh Hashanah due to the doubt of whether Elul was made into a leap month.

Explanation (cont.): If people would not know when Elul started, they would not know when the thirtieth day of Elul would be.

Implied Question: Five bad things happened on the seventeenth of Tamuz as well, as stated in the Mishnah in Tanis (26a). (Why is the ninth of Av deemed worse than the seventeenth of Tamuz?)

Answer #1: However, the destruction of the Beis Hamikdash was much worse (than these things).

Answer #2: Additionally, it is incomparable to the ninth of Av, as the same tragedy (destruction of the Beis Hamikdash) happened twice (Bayis Rishon and Bayis Sheini) on that same day.

Explanation: This is referring to the first Beis Hamikdash. However, the second Beis Hamikdash was breached on the seventeenth of Tamuz, which is why we make the seventeenth a fast day.

Observation: This same Beraisa is quoted in the Yerushalmi, but it instead says that the first Beis Hamikdash was also breached on the seventeenth of Tamuz.

Implied Question: This is despite the fact that the Pasuk explicitly states that it happened on the ninth of Tamuz. (How can the Yerushalmi contradict a Pasuk?)

Answer: The Yerushalmi understands that the people were confused as to the correct date, and it therefore argues on our Gemara. This means that since they were very bothered by the events they made a mistake afterwards in recalling when the walls were breached, and the Pasuk did not want to change its date from what the people afterwards thought (that it had been on the ninth).

Observation: The Gemara in Tanis (29a) asks that the Pesukim seem to contradict each other. At the end of Melachim the Pasuk states that it was burned on the seventh of Av, while in Yirmiyah it says it was on the tenth of Av. The Gemara answers that the enemies entered the Heichal, ate, and drank for three days. On (the second half of) the ninth of Av towards evening they lit the fire, and it burned until sunset on the tenth of Av.

Implied Question: The Gemara could not have asked from the Mishnah that states they used to send messengers to state when Rosh Chodesh Kislev was due to Chanukah. (Why isn't this proof that it was considered a Yom Tov?)

Answer: This is because it was not really considered a Yom Tov, and even so (the messengers are sent to ascertain that) we light candles to remember the miracle.