أَخْبَرَنَا قُتَيْبَةُ، قَالَ حَدَّثَنَا عَبِيدَةُ، عَنْ يَحْيَى بْنِ سَعِيدٍ، عَنْ أَنَسٍ، قَالَ بَالَ أَعْرَابِيٌّ فِي الْمَسْجِدِ فَأَمَرَ النَّبِيُّ صلى الله عليه وسلم بِدَلْوٍ مِنْ مَاءٍ فَصُبَّ عَلَيْهِ ‏.‏

It was narrated that Anas bin Malik said: "A Bedouin urinated in the Masjid, and the Prophet (PBUH) ordered that a bucket (be brought) and poured over it." Translation Not Available

Book Ref: Sunan An Nisai Book 1 Hadith 54
Web Ref:  Sunan An Nisai Vol 1 Book 1 Hadith 54