Ketubot 83 - 2nd Day of Rosh Hashana - September 27, 2 Tishrei

The Mishna brings different statements a husband can make to relinquish his rights to her usufruct ( nichsei melog ) property. Which language exempts him from which rights? Rabbi Shimon ben Gamliel disagrees regarding his right to inherit the property upon her death and holds that his right to inherit the property is a Torah law and he cannot make a stipulation against a law in the Torah. Why does it work for him to relinquish his rights by making a declaration, when in the case of a partnership, one who declares they want no share in the property does not relinquish one's rights as it is likely one said it out of anger or frustration and didn't actually mean it? How are the cases different? In the partnership case, what if they did a kinyan? Would it be effective? Why in the first case in the Mishna does the husband relinquish his rights only to the extent that she can sell the property? Why not the other rights instead or the other ones as well? Rabbi Yehuda states that to relinquish rights to the proceeds of the proceeds and the proceeds of those proceeds and so on, one needs to be very specific with the language. What aspect of the wording is the part that is critical – the words "proceeds or proceeds" or "forever?" If one only mentioned proceeds or proceeds and not proceeds alone, are the rights to the proceeds relinquished as well? Rav held like Rabbi Shimon ben Gamliel but not for the same reason. What was Rav's reason?