‘A'isha reported God’s messenger as saying, “If anyone dies when some fast due from him has been unfulfilled, his heir must fast on his behalf.” (Bukhari and Muslim.)
Hadith Referenceمشكوة المصابيح / كتاب الصوم / 2033
Hadith Gradingالألبانی:مُتَّفَقٌ عَلَيْهِ | زبیر علی زئی:متفق عليه
Hadith Takhrij´تحقيق و تخريج: محدث العصر حافظ زبير على زئي رحمه الله` «متفق عليه، رواه البخاري (1952) و مسلم (153/ 1147)»