Sahih al-Bukhari 224

Arabic

حَدَّثَنَا آدَمُ، قَالَ حَدَّثَنَا شُعْبَةُ، عَنِ الأَعْمَشِ، عَنْ أَبِي وَائِلٍ، عَنْ حُذَيْفَةَ، قَالَ أَتَى النَّبِيُّ صلى الله عليه وسلم سُبَاطَةَ قَوْمٍ فَبَالَ قَائِمًا، ثُمَّ دَعَا بِمَاءٍ، فَجِئْتُهُ بِمَاءٍ فَتَوَضَّأَ‏.‏

English translation

Narrated Hudhaifa:Once the Prophet (ﷺ) went to the dumps of some people and passed urine while standing. He then asked for water and so I brought it to him and he performed ablution

Reference: Sahih al-Bukhari 224, Book of Ablutions (Wudu'). English translation by Dr. Muhammad Muhsin Khan.