Arachin 23 - Responsibilities of a Loan Guarantor
A Ketubah is a husband's obligation to provide for his wife in case of his death or divorce. If one consecrated all of his possessions to the Temple, the Ketubah part is not consecrated, because it came prior. However, if the husband now wants to divorce his wife, we make him vow never to re-marry her, because we suspect that the divorce is just a ruse: she will collect the Ketubah, and he will re-marry her and live on that money - this is the opinion of Rabbi Eliezer. Rabbi Yehoshua says that he does not need to vow - either because people do not cheat on Temple, or because he can annul his consecration.
Rav Huna was poor, and his father, Moshe bar Atzri, promised to pay the Ketubah of his wife. Abbaye said, "Who would advise Rav Huna to divorce his wife and collect the money?" Rav Huna was a Kohen, who cannot re-marry his wife, and Abbaye remarked, "Poverty follows after the poor."
But maybe Moshe ben Atzri just wanted to help his son and was not sincere in his promise? - He accepted to be a guarantor even if his son does have the money, and such a guarantee is always binding.
Art: Tivadar Zemplenyi - The Poor Womans Home