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." (ID)
English reference (ID): Vol. 1, Book 7, Hadith 1757 (ID)
Arabic reference (ID): Book 7, Hadith 1829 (ID)