Abu Ayyub al-Ansari reported the Messenger of Allah ﷺ as saying:

it is not allowable for a Muslim to keep apart from his brother for more than three days. When they meet, this turns away from him, and that turns away from him. The better of the two is the one who initiates in salutation.

حَدَّثَنَا عَبْدُ اللَّهِ بْنُ مَسْلَمَةَ، عَنْ مَالِكٍ، عَنِ ابْنِ شِهَابٍ، عَنْ عَطَاءِ بْنِ يَزِيدَ اللَّيْثِيِّ، عَنْ أَبِي أَيُّوبَ الأَنْصَارِيِّ، أَنَّ رَسُولَ اللَّهِ ﷺ قَالَ
" لاَ يَحِلُّ لِمُسْلِمٍ أَنْ يَهْجُرَ أَخَاهُ فَوْقَ ثَلاَثَةِ أَيَّامٍ يَلْتَقِيَانِ فَيُعْرِضُ هَذَا وَيُعْرِضُ هَذَا وَخَيْرُهُمَا الَّذِي يَبْدَأُ بِالسَّلاَمِ " .