Sahih al-Bukhari, Book 78, Hadith 56 (In-Book) ⓘ

Narrated Anas bin Malik: A bedouin urinated in the mosque and the people ran to (beat) him. Allah's Messenger said, "Do not interrupt his urination (i.e. let him finish)." Then the Prophet asked for a tumbler of water and poured the water over the place of urine.

حَدَّثَنَا عَبْدُ اللَّهِ بْنُ عَبْدِ الْوَهَّابِ، حَدَّثَنَا حَمَّادُ بْنُ زَيْدٍ، عَنْ ثَابِتٍ، عَنْ أَنَسِ بْنِ مَالِكٍ، أَنَّ أَعْرَابِيًّا، بَالَ فِي الْمَسْجِدِ، فَقَامُوا إِلَيْهِ، فَقَالَ رَسُولُ اللَّهِ صلى الله عليه وسلم ‏ "‏ لا تُزْرِمُوهُ ‏" ‏‏.‏ ثُمَّ دَعَا بِدَلْوٍ مِنْ مَاءٍ فَصُبَّ عَلَيْهِ‏.‏