"Sa'd consulted the Messenger of Allah about a vow which his mother had to fulfill, but she died before doing so. The Messenger of Allah said: 'Fulfill it on her behalf.'" (Using translation from Nasāʾī 3659)
اسْتَفْتَى سَعْدٌ رَسُولَ اللهِ ﷺ فِي نَذْرٍ كَانَ عَلَى أُمِّهِ فَتُوُفِّيَتْ قَبْلَ أَنْ تَقْضِيَهُ فَقَالَ رَسُولُ اللهِ ﷺ «اقْضِهِ عَنْهَا»