Implied question: It says in Mo'ed Katan (28a) that children, lifespan and income do not depend on merit, rather, on Mazel (they are decreed from birth)!

Answer: Obviously, a great merit helps, like it says in Shabbos (156b) "Mazel does not apply to Yisrael."

However, it is not common that Mazel change, like is proven from the episode with R. Elazar ben Pedas in Ta'anis (25a. In spite of his great merits and dearness to Hash-m, his Mazel did not change. Hash-m offered to restart the world from the beginning, and perhaps he will receive a better Mazel!)

Explanation: This is called an addition based on what was decreed to deduct [from his allotted years] due to sin.

Implied question: It says in Chagigah (4b) regarding the women's hairdresser, [the angel of death said] "when I see a Chacham who pardons people who mistreat him, I add [years taken from someone else] to him. (This is unlike R. Akiva!)

Answer (Ri): It is even like R. Akiva. This is not called an addition, since initially the years were decreed for some person.

Question: Had Chizkiyah not prayed for himself, he would have died, and the prophecy would have been Batel (not fulfilled)!

Answer: You are forced to say that a Navi prophesizes only what is proper to occur if the person will not sin.

Question: If so, what is the proof from here that they added his own years? Even if they did not add to him, and he already lived all his years that were decreed for him, we could say that the prophecy was not fulfilled because he sinned [through not marrying]!

Had he not sinned, and he would have married in his first [decreed] years, he would have fathered a child!

Answer (Ri): Perhaps the generations were decreed to be born at the time and situation that they were born, and it was decreed that he father Menasheh in the added years. (Aruch l'Ner - therefore, these are considered years that were initially decreed for him!)

Explanation #1 (Rashi): Anyone who does not know this [that Achos Ishto is forbidden only in his wife's lifetime, should] go learn from a Rebbi [teaching Chumash to children]!

Question #1: In several places, the Tana teaches what is explicit in a verse!

Question #2: He needed to teach that if he divorced her and she died, he is permitted to her sister, to infer that if she did not die, she is forbidden!

This is not written explicitly. We needed to expound it above (8b) from "Aleha" - she is always forbidden in her lifetime, even if he divorced her.

Explanation #2 (Ri): [The clause about] his Yevamah is not needed. Since the Tana taught [the Heter of her sister after death of] his wife, all the more so regarding his Yevamah.

Observation: This is even like Rabanan of R. Akiva. Even though they hold that Kidushin Tofsin b'Chayavei Lavin, and Kidushin takes effect after Bi'ah, there is it is because it is Kidushin mid'Oraisa. The Bi'ah uprooted Zikah;

Here she is Zekukah to him. Kidushin takes effect only mid'Rabanan, and Chachamim did not enact Ma'amar after Ma'amar.

This is why the Gemara did not say on this "this is R. Akiva's opinion". This is unlike Rivan explained, that R. Gamliel holds like R. Akiva.

Explanation: This refers to after a Kosher Bi'ah. After a Pasul Bi'ah, e.g. Bi'ah after Get, [a second] Bi'ah takes effect after it, just like Ma'amar takes effect after it, like I will explain in the Gemara.

Explanation: This is even after a Chalitzah Pesulah.

Explanation: This is when he gave a Get Stam. If he [explicitly] gave a Get for the Ma'amar, she is permitted even to the Yavam;

We said above (32a) that even she is permitted. What he did (the Ma'amar), he removed.

Explanation: Here he did not teach "there is nothing after Chalitzah", because she still needs a Get for the Ma'amar already [given];

We teach it (there is nothing after Chalitzah) only when he need not do anything after Chalitzah.

Explanation (Rivan): There was no need to teach this at all;

Since he taught "if he gave a Get and did Chalitzah, there is nothing after Chalitzah", even though it is a Chalitzah Pesulah, all the more so there is nothing after a Kosher Chalitzah!

Rather, he teaches all possibilities [even if there is no Chidush].

Observation: Here we could ask that he should give a Get to one of them for his Ma'amar, and the other will be permitted! I explained above (32a).

Explanation: According to the opinion that Chalitzah Pesulah requires Lachzor (each Tzarah must do Chalitzah herself), they need two Chalitzos. "Tzerichos" refers also to Chalitzah.

Implied question: The very next case says that if he gave a Ma'amar and gave a Get, she needs a Get and Chalitzah. Why didn't it say they need Chalitzah, in the plural?

Answer: Since it taught "she needs a Get" in the singular, it discusses also Chalitzah in the singular.

Explanation: With a regular woman, there is no concern lest people say that since Chalitzah does not help, also Get does not help, since Chalitzah (removing the Yavam's shoe) and Keri'ah (the verses they say) do not apply a regular woman.

Suggestion: A Yevamah should require a Get and Chalitzah, lest people say that since Chalitzah helps by itself, also Get helps [by itself]!

Answer: People will not err about this, to exempt her without Chalitzah, for the verse explicitly requires Chalitzah;

However, here we are concerned lest they say that the verse obligates Chalitzah aside from the Get, which applies to all women;

They will say that since Get does not help by itself, also Chalitzah does not help [by itself], and come to do Bi'ah after Chalitzah.

Implied question: Now that it (Ma'amar) helps, we should be concerned lest people say that just like Bi'ah helps after Get and Ma'amar, it (Bi'ah) helps also after Bi'ah and Chalitzah, and they will come to do Bi'ah after Bi'ah, just like after Ma'amar!

Answer: [This is not a concern, for] also after Ma'amar, Bi'ah [of a different Yavam, or with a different Tzarah] is forbidden.