The Book of Purification
1/45. Chapter:
Leaving Any Restriction On The Amount Of Water
Sunan an-Nasai
أَخْبَرَنَا قُتَيْبَةُ، قَالَ حَدَّثَنَا حَمَّادٌ، عَنْ ثَابِتٍ، عَنْ أَنَسٍ، أَنَّ أَعْرَابِيًّا، بَالَ فِي الْمَسْجِدِ فَقَامَ إِلَيْهِ بَعْضُ الْقَوْمِ فَقَالَ رَسُولُ اللَّهِ صلى الله عليه وسلم " دَعُوهُ لاَ تُزْرِمُوهُ " . فَلَمَّا فَرَغَ دَعَا بِدَلْوٍ فَصَبَّهُ عَلَيْهِ . قَالَ أَبُو عَبْدِ الرَّحْمَنِ يَعْنِي لاَ تَقْطَعُوا عَلَيْهِ .
It was narrated from Anas that a Bedouin urinated in the Masjid, and some of the people went after him, but the Messenger of Allah (ﷺ) said: "Leave him and do not restrain him." When he had finished he called for a bucket (of water) and poured it over it. [1] Abu 'Abdur-Rahman (An-Nasa'i) said: "Meaning: 'Do not interrupt him.'" [1]The author will cite this narration again in No. 330 as a possible proof for setting the minimum, since it mentions "a bucket" as if this is the minium amount required.
Reference : Sunan an-Nasa'i 53In-book reference : Book 1, Hadith 53English translation : Vol. 1, Book 1, Hadith 53