Sahih al-Bukhari 2761
Sahih al-Bukhari · Book 55: Wills and Testaments (Wasaayaa) · Charity on behalf of a person who dies suddenly. And the execution of the vows.
Narrated Ibn `Abbas:
حَدَّثَنَا عَبْدُ اللَّهِ بْنُ يُوسُفَ ، أَخْبَرَنَا مَالِكٌ ، عَنِ ابْنِ شِهَابٍ ، عَنْ عُبَيْدِ اللَّهِ بْنِ عَبْدِ اللَّهِ ، عَنِ ابْنِ عَبَّاسٍ ـ رضى الله عنهما ـ أَنَّ سَعْدَ بْنَ عُبَادَةَ ـ رضى الله عنه ـ اسْتَفْتَى رَسُولَ اللَّهِ صلى الله عليه وسلم فَقَالَ إِنَّ أُمِّي مَاتَتْ وَعَلَيْهَا نَذْرٌ. فَقَالَ " اقْضِهِ عَنْهَا " .
Sa`d bin Ubada consulted Allah's Messenger (ﷺ) saying, "My mother died and she had an unfulfilled vow." The Prophet (ﷺ) said, "Fulfill it on her behalf."