I saw the Messenger of Allah ﷺ drinking both standing and sitting.
رأيت رسول الله ﷺ يشرب قائما وقاعدا.
Tirmidhi narrated it in his Sunan (1883) and in Shamail (209), as did Abu Dawud (653), Ibn Majah (931), and Ahmad (6660), all of them through the route of Amr bin Shuayb, from his father, from his grandfather Abdullah bin Amr, who said, and then he mentioned it.Its chain is hasan on account of Amr bin Shuayb, for his hadith is hasan. Tirmidhi also graded it hasan.