- Machlokes whether years can be added onto a person’s lifespan
The third contradiction that Menashe brought against Yeshaya addressed the question of whether Hashem will add years unto a person’s life. Moshe had said regarding the berachos that Hashem will bestow upon the Jewish people: "את מספר ימיך אמלא" – the number of your days I shall fill out, which implies that Hashem will not add years onto one’s life. But Yeshaya had said to Menashe’s father, Chizkiyahu: "והוספתי על ימיך חמש עשרה שנה" – Hashem said, “I will add fifteen years to your life.” The Gemara brings a Baraisa, that the correct resolution to this contradiction is a machlokes Tannaim, for it was taught in a Baraisa: "את מספר ימיך אמלא" – The number of your days I will fill out. Rebbe Akiva holds: אלו שני דורות – This refers to the years of the generations, referring to one’s lifespan. זכה משלימין לו לא זכה פוחתין לו – If one merits, they complete the years for him, and if he does not merit, they shorten the years for him. But the Chochomim say: זכה מוסיפים לו לא זכה פוחתין לו – If he merits, they increase the years for him, adding years onto his lifespan, but if he does not merit, they shorten his lifespan. When the Rabbanon tried to bring a proof from the fact that Yeshaya told Chizkiyahu that fifteen years were to be added onto his life, Rebbe Akiva responded that these fifteen years originally belonged to Chizkiyahu.
- Machlokes if there is a get after a get
The opening Mishnah of the fifth perek states: Rabban Gamliel says: אין גט אחר גט ואין מאמר אחר מאמר – There is no validity to a get after a get, nor to a maamar after a maamar, but the Chochomim hold that there is a get after a get and maamar after a maamar. Rashi explains that according to Rabban Gamliel, if a yavam gave two yevamahs from one deceased brother, each a get, the get given to the second yevamah is not valid, and the yavam is not forbidden to marry her relatives. Rabban Gamliel has a safek whether a get given by a yavam is effective in rejecting the yevamah from yibum. If the first get is effective, then it is pakah the zikah (it dissolves the zikah) from all the yevamahs and all the brothers, like chalitzah, and the second get is regarded as having been given to a stranger. If it is not effective, then neither the get given to the first or second yevamah has any validity, and therefore the giver of the second get is permitted to marry her relatives. According to the Chochomim, the get is partially valid mid’Rabbanon, but does not uproot the zikah completely. It is effective to preclude the yavam from doing yibum with the first yevamah but he must still do chalitzah. Since there is some zikah still extant, a get given to the second yevamah is also valid and prohibits the yavam from marrying her relatives.
- Why according to the Rabbanon giving a get to one yevamah is effective
The Gemara explains the reason why according to the Rabbanon a get given to one yevamah is effective. It is because in general a get is effective for divorce, and if you would say that is has no effect when given to a yevamah, and does not disqualify her from yibum, people will say: גט להוציאה וחליצה להוציאה – A get releases a woman and chalitzah releases a woman, and since a get given to a yevamah has no effect in prohibiting yibum, so too chalitzah has no effect in prohibiting yibum. People will not realize that in the case of chalitzah, she is prohibited to the yavam because of the issur: כיון שלא בנה שוב לא יבנה - Once he did not build, he shall never again build.