Sahih Muslim Book - 54, Hadith - 7549

حَدَّثَنَا أَبُو بَكْرِ بْنُ أَبِى شَيْبَةَ حَدَّثَنَا غُنْدَرٌ عَنْ شُعْبَةَ ح وَحَدَّثَنَا مُحَمَّدُ بْنُ الْمُثَنَّى وَابْنُ بَشَّارٍ - وَاللَّفْظُ لاِبْنِ الْمُثَنَّى - قَالاَ حَدَّثَنَا مُحَمَّدُ بْنُ جَعْفَرٍ عَنْ شُعْبَةَ عَنْ أَبِى إِسْحَاقَ قَالَ سَمِعْتُ الْبَرَاءَ يَقُولُ كَانَتِ الأَنْصَارُ إِذَا حَجُّوا فَرَجَعُوا لَمْ يَدْخُلُوا الْبُيُوتَ إِلاَّ مِنْ ظُهُورِهَا - قَالَ - فَجَاءَ رَجُلٌ مِنَ الأَنْصَارِ فَدَخَلَ مِنْ بَابِهِ فَقِيلَ لَهُ فِى ذَلِكَ فَنَزَلَتْ هَذِهِ الآيَةُ ( لَيْسَ الْبِرُّ بِأَنْ تَأْتُوا الْبُيُوتَ مِنْ ظُهُورِهَا ).

It was narrated that Abu Ishaq said: "I heard Al-Bara' say: 'When the Ansar performed Hajj and came back, they used to enter their houses only from the back. An Ansari man came and entered his house through the door, and something was said to him about that. Then this Verse was revealed: It is not Al-Birr (piety, righteousness) that you enter the houses from the back..."