Sunan an-Nasā'ī 54✓ 5Sahih
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 (ﷺ) ordered that a bucket (be brought) and poured over it