Ketubot 87 - Repairing trust
Earlier we learned that a husband may at times impose an oath on his wife, that she did not embezzle any of his property. We also mentioned that the possibility of this oath may lead to a mistrust between the husband and the wife.
To prevent this, the husband may write for her a document stating that he "Will have no right to impose an oath or vow on her," and he then waive this right, although he can still impose the oath on her successor. He may go further and give up the right to impose an oath on others involved as well.
The purpose of this oath was often to verify that the wife has not as yet collected her Ketubah, and that she is coming with a valid claim on the full amount. However, there was a strong incentive for the widow to take this oath, even if in truth she already collected some or all of the payment, and rationalize that she is indeed entitled to extra compensation, because of the care that she will have to give to the orphans. The courts stopped accepting this oath, and widows had no way of collecting the Ketubah. To rectify that, the Sages gave the orphans the right to ask her to pronounce a vow (such as "The use of my husband's property is prohibited to me if I embezzled") and then she gets the Ketubah.
The standard case where an oath would be present is where the husband claims that he paid his wife the Ketubah, and she says she received only a partial payment. The oath is in order because the one who pays usually remembers well his payment, but the one who receives is not as careful about the details. The oath makes him better go through his recollections.
Art: The Orphan By Walter Langley