Sahih Muslim Book - 45, Hadith - 6544

حَدَّثَنَا قُتَيْبَةُ بْنُ سَعِيدٍ ، عَنْ مَالِكِ بْنِ أَنَسٍ ، فِيمَا قُرِئَ عَلَيْهِ ، عَنْ سُهَيْلٍ ، عَنْ أَبِيهِ ، عَنْ أَبِي هُرَيْرَةَ ، أَنَّ رَسُولَ اللهِ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ، قَالَ: تُفْتَحُ أَبْوَابُ الْجَنَّةِ يَوْمَ الإِثْنَيْنِ ، وَيَوْمَ الْخَمِيسِ ، فَيُغْفَرُ لِكُلِّ عَبْدٍ لاَ يُشْرِكُ بِاللَّهِ شَيْئًا ، إِلاَّ رَجُلاً كَانَتْ بَيْنَهُ وَبَيْنَ أَخِيهِ شَحْنَاءُ ، فَيُقَالُ: أَنْظِرُوا هَذَيْنِ حَتَّى يَصْطَلِحَا ، أَنْظِرُوا هَذَيْنِ حَتَّى يَصْطَلِحَا ، أَنْظِرُوا هَذَيْنِ حَتَّى يَصْطَلِحَا.

It was narrated from Abu Hurairah that the Messenger of Allah (s.a.w) said: "The gates of Paradise are opened on Mondays and Thursdays, and every slave (of Allah) who does not associate anything with Allah is forgiven, except a man between whom and his brother there is some grudge. It is said said: 'Wait for these two until they reconcile, wait for these two until they reconcile, wait for these two until they reconcile."'