Rasulullah (sallallahu ‘alaihi wasallam) took the meat and broke it into pieces with his blessed teeth. Placing the meat into a bowl, he bade the others to eat saying, “Take the name of Allah Ta‘ala and start eating.” There was such blessing in the food that each and every one of them ate to their fill from this one small dish of meat. In fact, there was a little left over as well, whereas the amount of food only seemed sufficient for one person.
Rasulullah (sallallahu ‘alaihi wasallam) then instructed me to bring the bowl of milk and serve it to all of them. All of them were quenched with just this one bowl whereas one bowl of milk is not large in quantity. Let alone forty people, a bowl of milk is barely enough for just one person.
When they finished eating, Rasulullah (sallallahu ‘alaihi wasallam) wished to address them. However, Abu Lahab said, “O people! Wake up and leave! Muhammed has cast a spell over your food today. We have never witnessed a spell such as this before today.” The moment he said this, the people departed and Rasulullah (sallallahu ‘alaihi wasallam) did not get a chance to address them.
The following day, Rasulullah (sallallahu ‘alaihi wasallam) again instructed Hazrat ‘Ali (radhiyallahu ‘anhu) to prepare the same meal. When they finished eating, Rasulullah (sallallahu ‘alaihi wasallam) said, “What I am going to present to you is such that nobody has presented anything better than it to his people. I have come to inform you about this world as well as the next.”
(Extracted from Seeratul Mustafa 1/173)