I saw Ali perform the noon prayer, then sit to attend to people's needs. When the time for the afternoon prayer came, a vessel of water was brought to him. He took a handful from it and wiped his face, his forearms, his head, and his feet. Then he took what remained and drank it while standing, saying, "People dislike this, but I saw the Messenger of Allah ﷺ do it. This is the ablution of one who has not broken his prior ablution."
رأيت عليا رضي الله عنه صلى الظهر، ثم قعد لحوائج الناس، فلما حضرت العصر أتي بتور من ماء، فأخذ منه كفا فمسح به وجهه وذراعيه ورأسه ورجليه، ثم أخذ فضله فشرب قائما، وقال: إن الناس يكرهون هذا، وقد رأيت رسول الله ﷺ يفعله، وهذا وضوء من لم يحدث.
Nasai (130) narrated it from Amr bin Yazid, who said, Bahz bin Assad narrated to us, who said, Shuba narrated to us, from Abdul-Malik bin Maysara, who said, I heard Nazal bin Sabra, and he mentioned something similar. Nasai gave it the chapter heading, "The description of wudu performed without a state of ritual impurity."Ibn Khuzayma narrated it in his Sahih (16) via Muhammad bin Jafar, who said, Shuba narrated to us with the same wording. He gave it the chapter heading, "The description of the wudu of the Prophet ﷺ while in a state of purity, without any state of ritual impurity that would necessitate wudu."The origin of the hadith is in Sahih Bukhari, in the Book of Drinks (5616), from Adam, from Shuba with the same chain, and its wording is, "He prayed Dhuhr, then sat attending to people's needs in the open square of Kufa, until the time for Asr prayer came. Then water was brought to him and he drank, and washed his face and hands, and he mentioned his head and his feet, then he stood up and drank what remained of it while standing. Then he said, 'Some people dislike drinking while standing, but the Prophet ﷺ did just as I have done.'"Bukhari, may Allah have mercy on him, preferred the narration of Adam over that of Bahz bin Assad, because he mentioned in his narration the washing of the face and hands according to what is well known. As for his statement, "and he mentioned his head and his feet," he perhaps meant by it wiping them, since most of the narrators said something similar.Bayhaqi said in Sunan al-Kubra (1/75), after narrating the hadith via Adam, "In this established hadith there is evidence that the hadith reported from the Prophet ﷺ about wiping over the feet, if it is sahih, was only meant to apply when he was in a state of purity, not in a state of ritual impurity, except that some narrators seem to have abridged the hadith and did not transmit his statement, 'This is the wudu of one who has not had a hadath.'"