The Messenger of Allah ﷺ was eating a meal with six of his companions when an Arabi came and devoured the food in just two mouthfuls. The Messenger of Allah ﷺ said, "Had he said 'Bismillah,' it would have sufficed all of you. So when any of you eats, let him say 'Bismillah.' If he forgets to say it at the beginning, let him say, 'Bismillah at its beginning and its end.'"
حدثنا أبو بكر بن أبي شيبة حدثنا يزيد بن هارون عن هشام الدستوائي عن بديل بن ميسرة عن عبد الله بن عبيد بن عمير
كان رسول الله ﷺ يأكل طعاما في ستة نفر من أصحابه فجاء أعرابي فأكله بلقمتين فقال رسول الله ﷺ أما أنه لو كان قال بسم الله لكفاكم فإذا أكل أحدكم طعاما فليقل بسم الله فإن نسي أن يقول بسم الله في أوله فليقل بسم الله في أوله وآخره
[Sahih]. Darimi narrated it (2/94, no. 2026) from the hadith of Yazid bin Harun with this chain, and Ibn Hibban graded it sahih (Mawarid, no. 1341).Tirmidhi also narrated it (no. 1858) through the route of Waki, from Hisham Dastawai, from Budayl bin Maysara Aqeeli, from Abdullah bin Ubayd bin Umayr, from Umm Kulthum, from Ayesha, with this chain, and he said, hasan sahih. Hakim graded it sahih (4/108), and Dhahabi agreed with him, and it is as they both said.