أَتَى النَّبِيُّ صلى الله عليه وسلم سُبَاطَةَ قَوْمٍ فَبَالَ قَائِمًا، ثُمَّ دَعَا بِمَاءٍ، فَجِئْتُهُ بِمَاءٍ فَتَوَضَّأَ.
Hudhayfah reported: The Prophet ﷺ came to the rubbish heap of some people and urinated standing. Then he called for water. I brought him water, and he performed ablution (wudu).
also in Sahih al-Bukhari 225, Sahih al-Bukhari 226