Related על בבא בתרא 252:12

"[Be betrothed to me] with the understanding that if I die you will not bound to a levir"—she is betrothed but his stipulation is invalid, for he stipulated against what was written in the Torah, and anyone who stipulates against what is written in the Torah, his stipulation is invalid. "With the understanding that I will have no responsibility for you for clothing or sex"—she is betrothed but his stipulation is invalid. This is the pneumonic: Anyone who stipulates against what is written in the Torah regarding a monetary matter—his stipulation stands; with a non-monetary matter—his stipulation is invalid.

Rabbi Yehudah says: [The husband] can always eat the fruits' fruit [i.e. the interest's interest, even if he said in the ketubah that he gives up access to the fruit from her property]. How so? He can sell the fruit and buy with [that money] land, and he can eat the fruit. Rabban Shimon ben Gamliel and Rabbi Yohanan ben Berokah say: If she dies, he inherits it [the fruit, even if he said he wouldn't have access to it in the ketubah], for she made a stipulation against what was written in the Torah and anyone who stipulates against what is written in the Torah, his stipulation is null and void.