Anas reported that Messenger of Allah ﷺ established fraternity between Abu Ubaida b. Jarrah and Abu Talha.  

أَنَّ رَسُولَ اللَّهِ ﷺ آخَى بَيْنَ أَبِي عُبَيْدَةَ بْنِ الْجَرَّاحِ وَبَيْنَ أَبِي طَلْحَةَ  

You must have heard this that Messenger of Allah ﷺ said: There is no alliance (hilf) of brotherhood in Islam. Anas said: Messenger of Allah ﷺ established the bond of fraternity between the Quraish and the Ansar in his home.  

أَنَّ رَسُولَ اللَّهِ ﷺ قَالَ لاَ حِلْفَ فِي الإِسْلاَمِ فَقَالَ أَنَسٌ قَدْ حَالَفَ رَسُولُ اللَّهِ ﷺ بَيْنَ قُرَيْشٍ وَالأَنْصَارِ فِي دَارِهِ  

Anas reported Messenger of Allah ﷺ established fraternity between the Quraish and the Ansar in his house at Medina.  

حَالَفَ رَسُولُ اللَّهِ ﷺ بَيْنَ قُرَيْشٍ وَالأَنْصَارِ فِي دَارِهِ الَّتِي بِالْمَدِينَةِ  

There is no alliance (hilf) in Islam but (the hilf) established in the pre-Islamic days (for good). Islam intensifies and strengthens it.  

قَالَ رَسُولُ اللَّهِ ﷺ لاَ حِلْفَ فِي الإِسْلاَمِ وَأَيُّمَا حِلْفٍ كَانَ فِي الْجَاهِلِيَّةِ لَمْ يَزِدْهُ الإِسْلاَمُ إِلاَّ شِدَّةً