Narrated Anas bin Malik: The Prophet saw a Bedouin making water in the mosque and told the people not to disturb him. When he finished, the Prophet asked for some water and poured it over (the urine).
Hadith ReferenceSahih Bukhari / The Book of Wudu (Ablution) / Hadith: 219
Hadith Gradingمحدثین:أحاديث صحيح البخاريّ كلّها صحيحة