Sahih al-Bukhari 4681

Arabic

حَدَّثَنَا الْحَسَنُ بْنُ مُحَمَّدِ بْنِ صَبَّاحٍ، حَدَّثَنَا حَجَّاجٌ، قَالَ قَالَ ابْنُ جُرَيْجٍ أَخْبَرَنِي مُحَمَّدُ بْنُ عَبَّادِ بْنِ جَعْفَرٍ، أَنَّهُ سَمِعَ ابْنَ عَبَّاسٍ، يَقْرَأُ ‏{‏أَلاَ إِنَّهُمْ تَثْنَوْنِي صُدُورُهُمْ‏}‏ قَالَ سَأَلْتُهُ عَنْهَا فَقَالَ أُنَاسٌ كَانُوا يَسْتَحْيُونَ أَنْ يَتَخَلَّوْا فَيُفْضُوا إِلَى السَّمَاءِ، وَأَنْ يُجَامِعُوا نِسَاءَهُمْ فَيُفْضُوا إِلَى السَّمَاءِ، فَنَزَلَ ذَلِكَ فِيهِمْ‏.‏

English translation

Narrated Muhammad bin `Abbas bin Ja`far:That he heard Ibn `Abbas reciting: "No doubt! They fold up their breasts." (11.5) and asked him about its explanation. He said, "Some people used to hide themselves while answering the call of nature in an open space lest they be exposed to the sky, and also when they had sexual relation with their wives in an open space lest they be exposed to the sky, so the above revelation was sent down regarding them

Reference: Sahih al-Bukhari 4681, Book of Prophetic Commentary on the Qur'an (Tafseer of the Prophet (pbuh)). English translation by Dr. Muhammad Muhsin Khan.