Sahih al-Bukhari 161
Book 4: Ablutions (Wudu') · Narrated by Abu Huraira
Arabic
حَدَّثَنَا عَبْدَانُ، قَالَ أَخْبَرَنَا عَبْدُ اللَّهِ، قَالَ أَخْبَرَنَا يُونُسُ، عَنِ الزُّهْرِيِّ، قَالَ أَخْبَرَنِي أَبُو إِدْرِيسَ، أَنَّهُ سَمِعَ أَبَا هُرَيْرَةَ، عَنِ النَّبِيِّ صلى الله عليه وسلم أَنَّهُ قَالَ " مَنْ تَوَضَّأَ فَلْيَسْتَنْثِرْ، وَمَنِ اسْتَجْمَرَ فَلْيُوتِرْ ".
English translation
Narrated Abu Huraira:The Prophet (ﷺ) said, "Whoever performs ablution should clean his nose with water by putting the water in it and then blowing it out, and whoever cleans his private parts with stones should do it with odd number of stones
Reference: Sahih al-Bukhari 161, Book of Ablutions (Wudu'). English translation by Dr. Muhammad Muhsin Khan.