Al-Wahshiyyi ibn Harb radiallaahu ‘anhu related that some of the Companions of Allaah’s Messenger sallallaahu ‘alayhi wa sallam said:
O Messenger of Allaah! We eat, but do not become satisfied.
So he said to them: “Perhaps you eat separately?”
So they replied: Yes.
So he said: “Eat your food collectively, mention the Name of Allaah upon it, then there will be blessings for you in it.”[1]
Shaykh Ibn al-’Uthaymeen said:
“This indicates that it is essential to eat collectively from a single plate. So if there are five or ten people, they should eat collectively from a single dish, depending upon the situation. Indeed, doing so is a cause for barakah (blessings) to descend, whilst eating separately is a cause for barakah to depart.”[2]
[1] Hasan: Related by Abu Daawood (no.3764). It was authenticated by al-Haafidh al-’lraaqee in his Takhreejul-lhyaa (214).
[2] Sharh Riyaadhus-Saaliheen (7/231) of Ibn al-’Uthaymeen.
http://salaf-us-saalih.com/2011/06/07/eating-collectively-from-a-single-plate/