Forty Hadith of Shah Waliullah Dehlawi 11

لَا یَحِلُّ لِمُؤمِنٍ اَنْ یَّجُهْرَ أخَاهُ فَوقَ ثَلَاثَةِ أیَّامٍ

It is unlawful for a believer to sever relations with his brother for more than three days