حَدَّثَنَا مُسَدَّدٌ، حَدَّثَنَا سُفْيَانُ، عَنْ عَاصِمٍ الأَحْوَلِ، قَالَ سَمِعْتُ أَنَسَ بْنَ مَالِكٍ، يَقُولُ حَالَفَ رَسُولُ اللَّهِ صلى الله عليه وسلم بَيْنَ الْمُهَاجِرِينَ وَالأَنْصَارِ فِي دَارِنَا ‏.‏ فَقِيلَ لَهُ أَلَيْسَ قَالَ رَسُولُ اللَّهِ صلى الله عليه وسلم ‏"‏ لاَ حِلْفَ فِي الإِسْلاَمِ ‏"‏ ‏.‏ فَقَالَ حَالَفَ رَسُولُ اللَّهِ صلى الله عليه وسلم بَيْنَ الْمُهَاجِرِينَ وَالأَنْصَارِ فِي دَارِنَا ‏.‏ مَرَّتَيْنِ أَوْ ثَلاَثًا

Narrated Anas bin Malik: The Messenger of Allah (PBUH) established an alliance (of brotherhood) between the Emigrants and the Helpers in our house. He was asked: Did not the Messenger of Allah (PBUH) say: There is no alliance in Islam ? He replied: The Messenger of Allah (PBUH) established an alliance between the Emigrants and the Helpers in our house. This he said twice or thrice. Translation Not Available

Book Ref: Sunan Abi Dawud Book 19 Hadith 2926
Web Ref:  Sunan Abi Dawud Book 18 Hadith 2920