Mishkat al-Masabih 4096

‘Ali prayed the noon prayer, then held a session to attend to the people’s needs in the open square of Kufa till the time of the afternoon prayer came. He was then brought water, drank some, washed his face and hands, the transmitter also mentioning his head and his feet, then stood up and drank what was left while standing. He then said, "Some people disapprove of drinking while standing, but the Prophet did as I have done." Bukhari transmitted it.