Section: If an insolvent person dies leaving slaves, and the month of Shawwal begins before they are divided among the creditors, their fitra is the responsibility of the heirs, because debt does not prevent the transfer of the estate; rather, it merely remains as a pledge for the debt, and the fitra of a pledged item is the responsibility of its owner.
Section: If his slaves, or those he provides maintenance for, die after the obligation of fitra has been established, it does not lapse, because it is a debt established in his liability due to his slave, and thus it does not lapse with his death, just as if the slave had incurred a debt with his permission, it would become an obligation in his [the owner's] liability. Furthermore, zakat on wealth does not lapse upon its destruction; therefore, zakat al-fitr is even more deserving of this [rule], for zakat on wealth attaches to the actual property according to one of the two narrations, whereas zakat al-fitr is the opposite.
Chapters on Voluntary Charity: It is recommended at all times, according to the words of the Almighty: {Who is it that would loan Allah a goodly loan so He may multiply it for him many times over?} [Quran 2:245]. He commanded charity in many verses, urged it, and encouraged it. Abu Salih narrated from Abu Hurayrah, who said: The Messenger of Allah (may Allah bless him and grant him peace) said: "Whoever gives in charity the equivalent of a date from pure earnings—and nothing ascends to Allah except the pure—Allah the Almighty accepts it with His Right hand, then nurtures it for its owner just as one of you nurtures his foal, until it becomes like a mountain." Muttafaq 'alayh (agreed upon). Charity given in secret...
(6) In (A) and (B): "annahu". (7) Surah al-Baqarah 245. (8) Al-Falu: A foal separated from its mother. (9) Reported by al-Bukhari in: The Chapter of 'Abd Allah ibn Munir, from the Book of Zakat; and in: The Chapter of the saying of Allah the Almighty: {The angels and the Spirit ascend to Him}, from the Book of Tawhid. Sahih al-Bukhari 2/134, 5/154. And by Muslim in: The Chapter of Acceptance of Charity from Pure Earnings and Its Nurturing, from the Book of Zakat. Sahih Muslim 2/702. It was also reported by al-Tirmidhi in: The Chapter on What Has Been Related Regarding the Virtue of Charity, from the Chapters of Zakat. 'Aridat al-Ahwadhi 3/163. And by al-Nasa'i in: The Chapter of Charity from Ghulul (unlawful gain), from the Book of Zakat. al-Mujtaba 5/43. And by Ibn Majah in: The Chapter on the Virtue of Charity, from the Book of Zakat. Sunan Ibn Majah 1/590. And by al-Darimi in: The Chapter on the Virtue of Charity, from the Book of Zakat. Sunan al-Darimi 1/395. And by Imam Malik in: The Chapter on Encouragement to Give Charity, from the Book of Sadaqah (Charity). al-Muwatta 2/995. And by Imam Ahmad in: al-Musnad 2/331, 418, 419, 431, 538, 541, 381, 382, 404, 471.