Praise be to Allah, and may Allah’s peace and blessings be upon the Messenger of Allah, his family and his companions. Wa alaikum assalam wa rahmatullahi wa barakatuh. As to what follows: In response to your question, we say: Al-Bukhari and Muslim transmitted from the hadith of ‘Aishah (may Allah be pleased with him) that the Prophet (peace be upon him) said, “Allah's Messenger (peace be upon him) said, "Whoever died and he ought to have fasted (the missed days of Ramadan) then his heirs must fast on his behalf” [al-Bukhari (1952) and Muslim (1147)]. If the deceased did not fast the days that were due from him until he died then his heirs must fast on his behalf in compensation for those days. This is the opinion that is in line with the indication of the hadith of ‘Aishah.