Dia ul moqadasi writes in (al-ahadeeth) al-mukhtara that anas narrates that arab would serve each other in journeys. Once there was a man with abu bakar and umar who would serve them. Once they slept, and woke up. But he had not prepared food for them. They said: he sleeps a lot. So they woke him up. And said: go to prophet asws and tell them that abu bakar and umar are paying greetings to you and seek permission from you. So Prophet asws said: they have taken their food. So they came to Prophet asws and said: with what did we take our food? So he asws said: I am seeing meat of your brother with you (exactly it would translate as: I am seeing meat of that man in your teeth………..