Sunan at-Tirmithiy كتاب الصوم باب ما جاء فى الصوم عن الميت

حَدَّثَنَا أَبُو سَعِيدٍ الأَشَجُّ حَدَّثَنَا أَبُو خَالِدٍ الأَحْمَرُ عَنِ الأَعْمَشِ عَنْ سَلَمَةَ بْنِ كُهَيْلٍ وَمُسْلِمٍ الْبَطِينِ عَنْ سَعِيدِ بْنِ جُبَيْرٍ وَعَطَاءٍ وَمُجَاهِدٍ عَنِ ابْنِ عَبَّاسٍ قَالَ جَاءَتِ امْرَأَةٌ إِلَى النَّبِىِّ صلى الله عليه وسلم فَقَالَتْ إِنَّ أُخْتِى مَاتَتْ وَعَلَيْهَا صَوْمُ شَهْرَيْنِ مُتَتَابِعَيْنِ. قَالَ أَرَأَيْتِ لَوْ كَانَ عَلَى أُخْتِكِ دَيْنٌ أَكُنْتِ تَقْضِينَهُ. قَالَتْ نَعَمْ. قَالَ فَحَقُّ اللَّهِ أَحَقُّ. قَالَ وَفِى الْبَابِ عَنْ بُرَيْدَةَ وَابْنِ عُمَرَ وَعَائِشَةَ.
A woman came to the Prophet, peace and blessings of God be upon him, and said, "My sister died before fulfilling a due fast of two consecutive months." The Prophet asked,"Had your sister been indebted, would you have settled her debt?" "Sure," replied the woman. The Prophet said, "Then God's debt is more deserving(1)." Footnote (1): This shows that if a person dies while a period of fasting is due, then an heir of the deceased should complete the debt of fasting.