Ketubot 87 - Shabbat October 1, 6 Tishrei

The Mishna discusses a case where a husband exempted his wife from swearing and vows. What type of swear is being referred to? Two opinions are brought. Rav Ashi’s version is that one of the opinions was referring to a different case in the Mishna. There are four different opinions as to which languages exempt her from vows to him, which exempt her from vows to the heirs and which do not exempt her at all. In which cases does a woman need to swear to receive her ketuba money. Are these obligations to swear by Torah law or by rabbinic law?