The Messenger of Allah ﷺ forbade a man to drink while standing.The narrator said, We asked Anas, "What about eating?"He replied, "That is even worse, or fouler."Ibn Bakr said, "Or more wicked."
حدثنا محمد بن جعفر ومحمد بن بكر قالا حدثنا سعيد عن قتادة
نهى رسول الله ﷺ أن يشرب الرجل قائما قال فقلنا لأنس فالطعام قال ذلك أشد أو أنتن قال ابن بكر أو أخبث
Its isnad is sahih. The hadith was narrated by Tirmidhi 4/300 no. 1879, in the chapter on drinks, ruling on drinking while standing, and he said, hasan sahih, and Darimi 2/162 no. 2127 similarly. This prohibition is understood as scholars' disapproval, because of what is reported in Muslim, that the Prophet ﷺ drank from a hanging waterskin while standing, as mentioned previously.