Sayyiduna Umayyah bin Makhshi (may Allah be pleased with him), who was one of the Companions of the Prophet (peace and blessings be upon him), said: The Messenger of Allah (peace and blessings be upon him) was sitting, and a man was eating and did not say Bismillah until only one morsel of his food remained. Then he said: "Bismillah, at its beginning and its end." The Messenger of Allah (peace and blessings be upon him) laughed, then said: "Satan kept eating with you, and when you mentioned the name of Allah, he vomited up everything that was in his stomach."
Hadith Referenceالمعجم الكبير للطبراني / باب الألف / 851