Hadith 3:192
He also said that when a desert Arab got up and passed water in the mosque the people took hold of him, but the Prophet said to them, “Leave him alone, and pour a bucket* of water over what he has passed, for you have been sent only to make things easy and not to make things difficult.” *The text has sajl au dhanub , the transmitter not being sure which word was used. Both mean a bucket. Bukhari transmitted it.
وَعَنْهُ قَالَ: قَامَ أَعْرَابِيٌّ فَبَالَ فِي الْمَسْجِدِ فَتَنَاوَلَهُ النَّاسُ فَقَالَ لَهُمُ النَّبِيُّ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ: «دَعُوهُ وَهَرِيقُوا عَلَى بَوْلِهِ سَجْلًا مِنْ مَاءٍ أَوْ ذَنُوبًا مِنْ مَاءٍ فَإِنَّمَا بُعِثْتُمْ مُيَسِّرِينَ وَلَمْ تُبْعَثُوا مُعَسِّرِينَ» . رَوَاهُ الْبُخَارِيُّ
Original Reference: Mishkat al-Masabih 491