Making up fasts on behalf of one who died after not fasting in Ramadaan due to sickness
Question

I would like an explanation of the hadeeth, “Whoever dies owing fasts, his heir should fast on his behalf.” There is a father who died this year due to a lengthy sickness, and he had not finished making up the days that he owed from the previous Ramadaan. Should one of his children fast on his behalf? Or is there no need for that?.
Praise be to Allah.If this man was sick with an illness for which there was no hope of a cure, he did not have to fast or make up the fasts, rather he should have fed one poor person for each day. If he did that during his lifetime, all well and good, otherwise his heirs have to feed the poor on his behalf. 
But if his sickness was one from which it was hoped that he might have recovered, then he did not have to fast in Ramadaan because of being sick, but he should have made them up. If he was not able to make them up because he was still sick, then he does not have to do anything, either fasting or feeding the poor, and his heirs do not have to fast or feed the poor on his behalf. 
But if he was able to make the fasts up but he did not do so, then it is mustahabb for his heirs to fast on his behalf the number of days that he did not fast. If they do not do that, they should feed one poor person for each day. 
Based on this, the meaning of the words of the Prophet (peace and blessings of Allaah be upon him) “Whoever dies owing fasts, his heir should fast on his behalf” is that if a person did not fast for a reason such as menses, travel or sickness from which he hoped to recover, and he was able to make them up but he did not do so, then it is mustahabb for his heirs to observe the fasts on his behalf. 
It says in ‘Awn al-Ma’bood (7/26): 
The scholars are unanimously agreed that if a person does not fast because of sickness or travelling then he does not have the opportunity to make them up until he dies, there is no sin on him and food does not have to be given to the poor on his behalf, except that Qataadah said that food should be given to the poor on his behalf, and that was also narrated from Tawoos. End quote. 
Shaykh Ibn ‘Uthaymeen (may Allaah have mercy on him) said in Majmoo’ al-Fataawa (19/what is makrooh and mustahabb and the ruling on making up missed fasts): 
If a person does not fast in Ramadaan because of sickness, then dies before he is able to make up the fasts, the matter is straightforward, praise be to Allaah, based on the texts, the reports and the opinions of the scholars. 
With regard to the texts, Allaah says (interpretation of the meaning): “but if any of you is ill or on a journey, the same number (should be made up) from other days” [al-Baqarah 2:184]. Allaah enjoins fasting an equal number of other days, but if a person dies before that then he has died before the time when it becomes obligatory. This is similar to the case of someone died before Ramadaan begins, so food does not have to be given to the poor on his behalf for the next Ramadaan, even if he died shortly before it began. 
Moreover, so long as this sick person is still sick, he does not have to fast, and if he dies without recovering, then he has died before fasting became obligatory for him, so food does not have to be given to the poor on his behalf, because giving food to the poor is an alternative to fasting, and if he does not have to fast then he does not have to do the alternative. 
This evidence from the Qur’aan indicates that if he is not able to fast, then nothing is required of him. 
With regard to the Sunnah, the Prophet (peace and blessings of Allaah be upon him) said: “Whoever dies owing fasts, his heir should fast on his behalf.” Narrated by al-Bukhaari (1952) and Muslim (1147). 
The meaning of the hadeeth is clear: if a person dies owing no fasts, then fasts should not be observed on his behalf. From the above it is known that if a sick person remains sick, he does not have to fast or make up the fasts so long as his sickness lasts. 
With regard to the words of the scholars: 
It says in al-Mughni (p. 241, vol. 3 of the Dar al-Manaar edition): 
To sum up, if a person dies owing fasts from Ramadaan, one of two scenarios must apply:  
The first scenario is if he died before he was able to fast, either because there was not enough time, or because he has an excuse such as sickness, travel or being unable to fast. In this case nothing needs to be done, according to the majority of scholars. It was narrated that Tawoos and Qataadah said that food must be given to the poor on his behalf, then he mentioned the reason for that and stated that it was invalid. 
Then he said (p. 341): 
The second scenario is if he died after he became able to make up the fasts. In that case one poor person must be fed for each day. This is the view of the majority of scholars, and was narrated from ‘Aa’ishah and Ibn ‘Abbaas… 
Then he said: Abu Thawr said: The fast must be observed on his behalf. This was the view of al-Shaafa’i, then he quoted as evidence for that the hadeeth of ‘Aa’ishah which we mentioned above. 
It says in Sharh al-Muhadhdhab (p. 343, vol. 6, Maktabat al-Irshad edition): 
The view of the scholars is that if a person dies owing fasts that he missed because of being sick or because he was travelling, or for some other reason, and he was not able to make them up before he died: 
We have mentioned that our view is that nothing is required of him, and fasts should not be observed on his behalf, nor should food be given to the poor on his behalf, and there is no difference of opinion among us. 
This was the view of Abu Haneefah, Maalik and the majority. Al-‘Abdari said: This is the view of all the scholars except Tawoos and Qataadah, who said that one poor person must be fed on his behalf for each day, then he mentioned a reason for that and stated that it was invalid. He said: al-Bayhaqi and others of our companions quoted as evidence for our view the hadeeth of Abu Hurayrah, according to which the Prophet (peace and blessings of Allaah be upon him) said: “If I tell you to do a thing, then do as much of it as you can.” Narrated by al-Bukhaari and Muslim. 
It says in al-Furoo’ (p. 39 vol. 3): 
If he delays making up the missed fast until he dies, if that was for a valid reason then nothing need be done, according to the three imams, because there is no evidence to that effect. 
Thus it is clear that there is nothing confusing about this issue, and that fasts need not be made up on behalf of one whose excuse remained valid until he died. Similarly, food need not be given to the poor on his behalf, unless he was sick with an illness from which there was no hope of recovery, in which case food should be given on his behalf, as in the case of an elderly person who cannot fast. Food should be given on his behalf, because this was required of him when he was alive, instead of fasting. There is no doubt about what the scholars stated about this issue, and you know from what we have written that there is virtual consensus, apart from that which was narrated from Tawoos and Qataadah. End quote. 
The following question is mentioned in Fataawa al-Lajnah al-Daa’imah (10/372): 
My mother was ill during Ramadaan in 97 CE, and she could not fast for 8 days of the month, and she died three months after Ramadaan. Should I fast eight days on her behalf? Can I delay it until after Ramadaan of 98, or can I give charity on her behalf? 
The answer was: 
If your mother recovered after the Ramadaan in which she missed eight days, and before she died there was enough time during which she could have made up those days but she did not, then it is mustahabb for you or one of your relatives to fast these eight days on her behalf, because the Prophet (peace and blessings of Allaah be upon him) said: “Whoever dies owing fasts, his heir should fast on his behalf.” Agreed upon. It is permissible to delay the fasts, but it is better to hasten to do them if one is able to. 
But if she remained sick and died when she was not able to make up the fasts, then they do not have to be made up, because she was not able to make them up, and because of the general meaning of the words of Allaah (interpretation of the meaning):  
“Allaah burdens not a person beyond his scope”
[al-Baqarah 2:286]
and 
“So keep your duty to Allaah and fear Him as much as you can”
[al-Taghaabun 64:16]
End quote. 
And Allaah knows best.