It wasnarrated from Ibn 'Umar that the Messenger of Allah (ﷺ)said:
'Whoever dies owing the fasts of a month, one poor person shouldbefed on his behalf for each day." (PT)
English reference (PT): Vol. 1, Book 7, Hadith 1757 (PT)
Arabic reference (PT): Book 7, Hadith 1829 (PT)