I saw the Messenger of Allah ﷺ come to the refuse heap of some people and urinate while standing. He then asked for water, so I brought it to him, and he performed ablution and wiped over his leather socks.
حدثنا هشيم قال الأعمش أخبرنا عن أبي وائل
رأيت رسول الله ﷺ أتى سباطة قوم فبال وهو قائم ثم دعا بماء فأتيته فتوضأ ومسح على خفيه
Its chain of transmission is sahih. Abu Waail is Shaqiq bin Salama. Bukhari related the hadith in 1/328, no. 224 (Fath), in the book of wudu, as did Muslim in 1/228, no. 173, Abu Dawud in 1/6, no. 23, Tirmidhi in 1/19, no. 13, who graded it sahih, and Nasai in 1/19, no. 18, all of them in the book of purification, and Humaydi in 1/210, no. 1442. It has already been mentioned at 18068, without the last phrase, on the authority of Mughira.