The Prophet ﷺ saw a Bedouin making water in the mosque and told the people not to disturb him. When he finished, the Prophet ﷺ asked for some water and poured it over (the urine).  

أَنَّ النَّبِيَّ ﷺ رَأَى أَعْرَابِيًّا يَبُولُ فِي الْمَسْجِدِ فَقَالَ دَعُوهُ حَتَّى إِذَا فَرَغَ دَعَا بِمَاءٍ فَصَبَّهُ عَلَيْهِ