It wasnarrated that Ibn 'Umar said:
"At the time of the Messenger ofAllah (ﷺ) we used to eat while walking, and drink while standingup." (JA)
English reference (JA): Vol. 4, Book 29, Hadith 3301 (JA)
Arabic reference (JA): Book 29, Hadith 3426 (JA)