حَدَّثَنِي أَبُو جَعْفَرٍ، مُحَمَّدُ بْنُ الصَّبَّاحِ حَدَّثَنَا حَفْصُ بْنُ غِيَاثٍ، حَدَّثَنَا عَاصِمٌ الأَحْوَلُ، قَالَ قِيلَ لأَنَسِ بْنِ مَالِكٍ بَلَغَكَ أَنَّ رَسُولَ اللَّهِ صلى الله عليه وسلم قَالَ ‏"‏ لاَ حِلْفَ فِي الإِسْلاَمِ ‏"‏ ‏.‏ فَقَالَ أَنَسٌ قَدْ حَالَفَ رَسُولُ اللَّهِ صلى الله عليه وسلم بَيْنَ قُرَيْشٍ وَالأَنْصَارِ فِي دَارِهِ ‏.‏

It was said to Anas b. Malik: You must have heard this that Allah's Messenger (PBUH) said: There is no alliance (hilf) of brotherhood in Islam. Anas said: Allah's Messenger (PBUH) established the bond of fraternity between the Quraish and the Ansar in his home. Translation Not Available

Book Ref: Sahih Muslim Book 44 Hadith 6144
Web Ref:  Sahih Muslim Book 31 Hadith 2529 a