Ketubot, Chapter Ten, Mishnah Six
This mishnah deals with cases where multiple parties are attempting to collect a debt.
If a man who was married to two wives sold his field, and the first wife wrote to the buyer, I have no claim whatsoever upon you, the second wife may take [the field] away from the buyer, and the first wife from the second, and the buyer from the first wife; and so they go on in turn until they arrange a compromise between them.
The same law applies also to a creditor and to a woman creditor.
In this case a man marries two women, but not simultaneously. At this point all of his property has a lien on it from the two Ketubot. Later he sells a field to a buyer, who gets the first wife to promise him that should her husband die, she will not collect that field as her ketubah. Then the husband dies and cannot repay either ketubah. The first wife cannot claim the field from the purchaser, because she relinquished that right. However, the second wife can collect from the purchaser (she did not relinquish any rights) and then the first wife can collect from the second wife, because her ketubah takes precedence. Then the buyer can take back the field from the first wife, because she relinquished her claim on that field, at which point the second wife can again claim from the purchaser. This process will continue in circles until they come up with a compromise.
The same is true with the case of a creditor, a borrower and two purchasers. A borrower has two fields and sells them to two different people, and the value of the each field is equal to the value of the debt. Then the creditor writes to the second purchaser that he will not collect from that field. If the borrower defaults he may collect from the first purchaser, and the first purchaser may collect from the second purchaser, from whom the creditor may collect. On and on this process would go until they reach a compromise.
The same would be true for a woman creditor, which means a woman whose husband owes her her ketubah. This is the same case as above. The husband sells two fields to two different people and the wife writes to the second one that she would not collect from his field. She may then collect from the first field, the first purchaser may collect from the second and the second from the wife.