The Messenger of Allah ﷺ said, "I do not eat while reclining."
حدثنا محمد بن كثير أخبرنا سفيان عن علي بن الأقمر قال سمعت
قال رسول الله ﷺ لا آكل متكئا
No references are available.
Bukhari included it in the Book of Foods, Chapter on eating while reclining, hadith no. 5398, from the hadith of Ali bin Aqmar, through this same chain.