عَنْ أَبِي هُرَيْرَةَ وَابْنِ عُمَرَ رَضِيَ اللَّهُ عَنْهُمْ قَالَا: قَالَ رَسُولُ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ: «لَا تَنْذُرُوا فَإِنَّ النَّذْرَ لَا يُغْنِي مِنَ الْقَدَرِ شَيْئًا وَإِنَّمَا يُسْتَخْرَجُ بِهِ من الْبَخِيل»

Ibn ‘Abbas told that Sa'd b. ‘Ubada asked the Prophet for a decision about a vow taken by his mother who had died before fulfilling it, and that he gave decision that he should fulfil it on her behalf. (Bukhari and Muslim.)