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
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
Messenger of Allah ﷺ said, "Do not hate one another, and do not be jealous of one another, and do not desert each other, and O, Allah's worshipers! Be brothers. Lo! It is not permissible for any Muslim to desert (not talk to) his brother (Muslim) for more than three days."
أَنَّ رَسُولَ اللَّهِ ﷺ قَالَ لاَ تَبَاغَضُوا وَلاَ تَحَاسَدُوا وَلاَ تَدَابَرُوا وَكُونُوا عِبَادَ اللَّهِ إِخْوَانًا وَلاَ يَحِلُّ لِمُسْلِمٍ أَنْ يَهْجُرَ أَخَاهُ فَوْقَ ثَلاَثَةِ أَيَّامٍ
Yahya related to me from Malik from Ibn Shihab from Ata ibn Yazid al-Laythi from Abu Ayyub al-Ansari that the Messenger of Allah ﷺ said, "It is not halal for a muslim to shun his brother for more than three nights, that is they meet, and this one turns away and that one turns away. The better of the two is the one who says the greeting first."
أَنَّ رَسُولَ اللَّهِ ﷺ قَالَ لاَ يَحِلُّ لِمُسْلِمٍ أَنْ يُهَاجِرَ أَخَاهُ فَوْقَ ثَلاَثِ لَيَالٍ يَلْتَقِيَانِ فَيُعْرِضُ هَذَا وَيُعْرِضُ هَذَا وَخَيْرُهُمَا الَّذِي يَبْدَأُ بِالسَّلاَمِ
Yahya related to me from Malik from Ibn Shihab from Anas ibn Malik that the Messenger of Allah ﷺ said, "Do not be angry with each other and do not envy each other and do not turn away from each other, and be slaves of Allah, brothers. It is not halal for a muslim to shun his brother for more than three nights."
أَنَّ رَسُولَ اللَّهِ ﷺ قَالَ لاَ تَبَاغَضُوا وَلاَ تَحَاسَدُوا وَلاَ تَدَابَرُوا وَكُونُوا عِبَادَ اللَّهِ إِخْوَانًا وَلاَ يَحِلُّ لِمُسْلِمٍ أَنْ يُهَاجِرَ أَخَاهُ فَوْقَ ثَلاَثِ لَيَالٍ
[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»
"It is not permissible for a woman who believes in Allah and the Last Day to mourn for more than three days, except for her husband." (Using translation from Nasāʾī 3526)
أَنَّ رَسُولَ اللهِ ﷺ قَالَ «لَا يَحِلُّ لِامْرَأَةٍ تُؤْمِنُ بِاللهِ أَنْ تُحِدَّ فَوْقَ ثَلَاثَةِ أَيَّامٍ إِلَّا عَلَى زَوْجٍ»
"لَا يَحِلُّ لِمُؤْمِنٍ أَنْ يَهْجُرَ أَخَاهُ فَوْقَ ثَلَاثةِ أَيَّامٍ".
"لَا يَحِلُّ لِمُسْلِمٍ أَنْ يَهْجُرَ أَخَاهُ فَوْقَ ثَلَاثٍ، إلا أَنْ يَكُونَ مِمَّنْ لَا يَأمَنُ بَوَائِقَهُ".
"لَا يَحِلُّ لِمُسْلِمٍ أَنْ يَهْجُرَ أَخَاهُ فَوْقَ ثَلَاثٍ".
"لَا يَحِلُّ لِرَجُلٍ مُسْلِمٍ أنْ يَهْجُرَ أخَاهُ فَوْقَ ثَلاثَةِ أيَّامٍ، وَالسَّابِقُ يَسْبِقُ إِلى الْجَنَّةِ".