The Messenger of Allah ﷺ told me to offer a sacrifice on his behalf, and I will continue to offer a sacrifice on his behalf forever. (Using translation from Aḥmad 843)
عَنِ النَّبِيِّ ﷺ وكبشٍ عَنْ نَفْسِهِ وَقَالَ «أَمَرَنِي رَسُولُ اللَّهِ ﷺ أَنْ أُضَحِّيَ عَنْهُ» فَأَنَا أُضَحِّي أَبَدًا