It is narrated from Sayyiduna Anas (may Allah be pleased with him) that the Noble Prophet (peace and blessings be upon him) forbade drinking water while standing. The narrator said: I asked Sayyiduna Anas (may Allah be pleased with him): And what about eating while standing? He replied: That is even worse.
Hadith Referenceسنن دارمي / من كتاب الاشربة / 2164
Sayyiduna Abu Hurairah (may Allah be pleased with him) narrated from the Noble Prophet (peace and blessings be upon him) that he saw a man drinking water while standing, so he said: "Vomit it out." The man asked: Why? He said: "Would you like to drink water with a cat?" He replied: No. He said: "A devil worse than a cat has drunk water with you."
Hadith Referenceسنن دارمي / من كتاب الاشربة / 2165