Sunan An-Nasai, Chapter: The Book of Purification

"I saw Ali (may Allah be pleased with him) praying Zuhr, then he sat to tend to the people's needs, and when the time for Asr came, a vessel of water was brought to him. He took a handful of it and wiped his face, forearms, head and feet with it, then he took what was left and drank standing up. He said: 'People dislike this, but I saw the Messenger of Allah (saw) doing it. This is the Wudu of one who has not committed Hadath." (Sahih)