‘Ali said “If I survive for the Christians of Banu Taghlib I shall kill fighters and captivate children for I had written a document between them and the Prophet ﷺ to the effect that they would not make their children Christian. Abu Dawud said “This is rejected (munkar) tradition and it has reached me from Ahmad (bin Hanbal) that he used to reject this tradition seriously. Abu ‘Ali said “Abu Dawud did not present this (tradition) in this second reading.”  

عَلِيٌّ لَئِنْ بَقِيتُ لِنَصَارَى بَنِي تَغْلِبَ لأَقْتُلَنَّ الْمُقَاتِلَةَ وَلأَسْبِيَنَّ الذُّرِّيَّةَ فَإِنِّي كَتَبْتُ الْكِتَابَ بَيْنَهُمْ وَبَيْنَ النَّبِيِّ ﷺ عَلَى أَنْ لاَ يُنَصِّرُوا أَبْنَاءَهُمْ  

"عن زياد بن جرير قال: قال عَلِىٌّ: لَئِنْ بَقيتُ لِنَصَارَى بَنِى تَغْلِبَ لأَقْتُلَنَّ الْمُقَاتِلَةَ، وَلأَسْبِيَنَّ الذُّرِّيَّةَ، فَإِنِّى كَتَبْتُ الْكتَابَ بَيْنَهُمْ وَبَيْنَ النَّبِىِّ ﷺ عَلَى أن لاَ يُنَصِّرُوا أَبْنَاءَهُمْ".