It is not permissible for a Muslim to have estranged relations with his brother beyond three days.  

أَنَّ رَسُولَ اللَّهِ ﷺ قَالَ لاَ يَحِلُّ لِلْمُؤْمِنِ أَنْ يَهْجُرَ أَخَاهُ فَوْقَ ثَلاَثَةِ أَيَّامٍ  

[Machine] The Messenger of Allah ﷺ said: "Fighting against a Muslim is disbelief, and insulting him is sinful. It is not permissible for a Muslim to abandon his brother for more than three days."  

قَالَ رَسُولُ اللهِ ﷺ قِتَالُ المسلم كُفْرٌ وَسِبَابُهُ فُسُوقٌ وَلا يَحِلُّ لِمُسْلِمٍ أَنْ يَهْجُرَ أَخَاهُ فَوْقَ ثَلاثَةِ أَيَّامٍ  

The Prophet ﷺ said: It is not allowable for a Muslim to keep apart from his brother for more than three days, for one who does so and dies will enter Hell. (Using translation from Abū Dāʾūd 4914)   

قَالَ رَسُولُ اللهِ ﷺ لَا يَحِلُّ لِمُسْلِمٍ أَنْ يَهْجُرَ أَخَاهُ فَوْقَ ثَلاثٍ  

[Machine] The Prophet of Allah ﷺ said, "It is not permissible for a Muslim to abandon his brother for more than three days."  

قَالَ رَسُولُ اللهِ ﷺ «لَا يَحِلُّ لِمُسْلِمٍ أَنْ يَهْجُرَ أَخَاهُ فَوْقَ ثَلَاثٍ»  

[Machine] The Messenger of Allah ﷺ said, "Killing a Muslim is disbelief, insulting him is wickedness, and it is not permissible for a Muslim to abandon his brother for more than three days."  

قَالَ رَسُولُ اللهِ ﷺ «قَتْلُ الْمُسْلِمِ كُفْرٌ وَسِبَابُهُ فُسُوقٌ وَلَا يَحِلُّ لِمُسْلِمٍ أَنْ يَهْجُرَ أَخَاهُ فَوْقَ ثَلَاثَةِ أَيَّامٍ»  

"لَا يَحِلُّ لِمُؤْمِنٍ أَنْ يَهْجُرَ أَخَاهُ فَوْقَ ثَلَاثةِ أَيَّامٍ".  

"لَا يَحِلُّ لِمُسْلِمٍ أَنْ يَهْجُرَ أَخَاهُ فَوْقَ ثَلَاثٍ".