حَدَّثَنَا وَكِيعٌ، حَدَّثَنَا فِطْرٌ، عَنِ الْمُنْذِرِ، عَنِ ابْنِ الْحَنَفِيَّةِ
قَالَ: قَالَ عَلِيٌّ رَضِيَ اللَّهُ عَنْهُ يَا رَسُولَ اللَّهِ أَرَأَيْتَ إِنْ وُلِدَ لِي بَعْدَكَ وَلَدٌ أُسَمِّيهِ بِاسْمِكَ وَأُكَنِّيهِ بِكُنْيَتِكَ قَالَ: نَعَمْ فَكَانَتْ رُخْصَةً مِنْ رَسُولِ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ لِعَلِيٍّ
Ali (رضي الله عنه) said: O Messenger of Allah (sallallahu alayhi wa sallam), if I have a son after you are gone, I will call him by your name and give him your kunyah. He said: ‘Yes.’ That was a concession from the Messenger of Allah (sallallahu alayhi wa sallam) to Ali.
Musnad Ahmad 691, Book 5, Musnad 'Ali Ibn Abi Talib, Hadith 163. 1 min read