وَحَدَّثَنَا إِسْحَاقُ بْنُ إِبْرَاهِيمَ، أَخْبَرَنَا عِيسَى بْنُ يُونُسَ، حَدَّثَنَا الأَعْمَشُ، عَنْ مُسْلِمٍ، الْبَطِينِ عَنْ سَعِيدِ بْنِ جُبَيْرٍ، عَنِ ابْنِ عَبَّاسٍ، - رضى الله عنهما - أَنَّ امْرَأَةً، أَتَتْ رَسُولَ اللَّهِ صلى الله عليه وسلم فَقَالَتْ إِنَّ أُمِّي مَاتَتْ وَعَلَيْهَا صَوْمُ شَهْرٍ ‏.‏ فَقَالَ ‏"‏ أَرَأَيْتِ لَوْ كَانَ عَلَيْهَا دَيْنٌ أَكُنْتِ تَقْضِينَهُ ‏"‏ ‏.‏ قَالَتْ نَعَمْ ‏.‏ قَالَ ‏"‏ فَدَيْنُ اللَّهِ أَحَقُّ بِالْقَضَاءِ ‏"‏ ‏.‏

Ibn 'Abbas (Allah be pleased with both of them) reported: A woman came to the Messenger of Allah (PBUH) and said: My mother has died, and fasts of a month are due from her. Thereupon he said: Don't you see that if debt was due from her, would you not pay it? She said: Yes (I would pay on her behalf). Thereupon he said: The debt of Allah deserves its payment more than (the payment of anyone else). Translation Not Available

Book Ref: Sahih Muslim Book 13 Hadith 2554
Web Ref:  Sahih Muslim Book 6 Hadith 1148 a