Musnad Ahmad

Abdu Khair, may Allah have mercy on him, says that once I saw that Sayyiduna Ali, may Allah be pleased with him, called for water to perform ablution, moistened his hands with the water, and wiped them over the upper part of his feet, and said: "This is the ablution of a person who is not without ablution." Then he said: "If I had not seen the Prophet, peace and blessings be upon him, wiping over the upper part of the feet in masah over the socks, I would have given the opinion that the lower part of the foot is more deserving of being wiped." Then he drank the leftover water from the ablution while standing and said: "Where are those people who think that in no circumstance is it permissible to drink water while standing?"