And in another report a woman came to the Prophet ﷺ and said, “Messenger of Allah, my mother has died while owing a vowed fast; should I fast on her behalf?” He replied, “Suppose your mother had a debt and you repaid it for her—would that settle the matter?” She said, “Yes.” He then said, “So fast on behalf of your mother.”

General meaning
Two separate narrations occur in this hadith, and the context indicates that they describe two distinct incidents, not one.

1. In the first, a man came to the Prophet ﷺ and informed him that his mother had died owing a month of fasting; he asked whether he should make it up for her.
2. In the second, a woman came to him ﷺ and told him that her mother had died owing a vowed fast; she asked whether she should fast for her.

He gave both of them the same ruling: they should discharge whatever fasts their parents still owed. He then presented them with an illustrative example to clarify the point: “If your parents owed a debt to another human being, would you pay it for them?” When they answered in the affirmative, he explained that the fast is a debt owed to Allah; if a human debt is to be repaid, then a debt owed to Allah is even more deserving of being settled.

Points derived from the hadith

1. The unrestricted wording of the first narration shows that a deceased person’s fasts may be made up on his behalf, whether they were vowed or originally obligatory.
2. The second narration specifically indicates that a vowed fast may be made up for the deceased.
3. Since the two narrations appear to relate to two separate individuals—a man and a woman—each one retains its own purport; the first is not restricted by the second but remains general.
4. The broad rationale given in the hadith encompasses debts owed to Allah and to other people, whether incurred by vow or imposed directly by the Sacred Law: all are to be discharged for the deceased. This was transmitted by our teacher ʿAbd al-Raḥmān al-Saʿdī from Taqī al-Dīn Ibn Taymiyyah, may Allah have mercy on them both.
5. The hadith affirms analogy (qiyās), one of the principal proofs employed by the majority of jurists. The Prophet ﷺ offered them a familiar example so the meaning would be clearer and nearer to their minds, for likening the unfamiliar to the familiar facilitates comprehension.
6. His statement, “A debt owed to Allah has even more right to be settled,” indicates that when the financial rights of Allah and of human beings compete within the estate of a deceased person, zakat and other divine dues take precedence. Some scholars, however, hold that the two kinds of rights are equal.