حَدَّثَنَا الْقَعْنَبِيُّ، قَالَ قَرَأْتُ عَلَى مَالِكٍ عَنِ ابْنِ شِهَابٍ، عَنْ عُبَيْدِ اللَّهِ بْنِ عَبْدِ اللَّهِ، عَنْ عَبْدِ اللَّهِ بْنِ عَبَّاسٍ، ‏:‏ أَنَّ سَعْدَ بْنَ عُبَادَةَ، اسْتَفْتَى رَسُولَ اللَّهِ صلى الله عليه وسلم فَقَالَ ‏:‏ إِنَّ أُمِّي مَاتَتْ وَعَلَيْهَا نَذْرٌ لَمْ تَقْضِهِ ‏.‏ فَقَالَ رَسُولُ اللَّهِ صلى الله عليه وسلم ‏"‏ اقْضِهِ عَنْهَا ‏"‏ ‏.‏

Narrated Ibn 'Abbas: Sa'd b. 'Ubadah asked the Messenger of Allah (PBUH): My Mother has died and she could not fulfill her vow which she had taken. The Messenger of Allah (PBUH) said: Fulfill it on her behalf. Translation Not Available

Book Ref: Sunan Abi Dawud Book 22 Hadith 3307
Web Ref:  Sunan Abi Dawud Book 21 Hadith 3301