Regarding a man abandoning his brother
حَدَّثَنَا عَبْدُ اللَّهِ بْنُ مَسْلَمَةَ، عَنْ مَالِكٍ، عَنِ ابْنِ شِهَابٍ، عَنْ أَنَسِ بْنِ مَالِكٍ، أَنَّ النَّبِيَّ صلى الله عليه وسلم قَالَ " لاَ تَبَاغَضُوا وَلاَ تَحَاسَدُوا وَلاَ تَدَابَرُوا وَكُونُوا عِبَادَ اللَّهِ إِخْوَانًا وَلاَ يَحِلُّ لِمُسْلِمٍ أَنْ يَهْجُرَ أَخَاهُ فَوْقَ ثَلاَثِ لَيَالٍ " .
Anas b. Malik reported the Messenger of Allah (May peace be upon him) as saying: Do not hate each other; do not envy each other; do not desert each other; and be the servants of Allah as brethren. It is not allowed for a Muslim to keep apart from his brother for more than three days.