Sahih al-Bukhari 176
Narrated Abu Huraira:
Allah's Messenger (ﷺ) said, "A person is considered in prayer as long as he is waiting for the prayer in the 
mosque as long as he does not do Hadath." A non-Arab man asked, "O Abu Huraira! What is 
Hadath?" I replied, "It is the passing of wind (from the anus) (that is one of the types of Hadath).
حَدَّثَنَا آدَمُ بْنُ أَبِي إِيَاسٍ، قَالَ حَدَّثَنَا ابْنُ أَبِي ذِئْبٍ، عَنْ سَعِيدٍ الْمَقْبُرِيِّ، عَنْ أَبِي هُرَيْرَةَ، قَالَ قَالَ النَّبِيُّ صلى الله عليه وسلم ‏
"‏ لاَ يَزَالُ الْعَبْدُ فِي صَلاَةٍ مَا كَانَ فِي الْمَسْجِدِ يَنْتَظِرُ الصَّلاَةَ، مَا لَمْ يُحْدِثْ ‏"‏‏.‏ فَقَالَ رَجُلٌ أَعْجَمِيٌّ مَا الْحَدَثُ يَا أَبَا هُرَيْرَةَ قَالَ الصَّوْتُ‏.‏ يَعْنِي الضَّرْطَةَ‏.‏