(12) باب مَا جَاءَ فِي الرُّخْصَةِ فِي الشُّرْبِ قَائِمًا
Narrated 'Amr bin Shu'aib:
From his father, from his grandfather who said: "I saw the Messenger of Allah (ﷺ) drinking while standing and sitting."[Abu 'Eisa said:] This Hadith is Hasan Sahih.
Reference: Jami` at-Tirmidhi 1883
In-book reference: Book 26, Hadith 23
English translation: Vol. 3, Book 24, Hadith 1883