Комментарий к Берешит 47:12

לפי הטף ACCORDING TO THEIR LITTLE ONES — according to the requirements of all their household.

לחם לפי הטף. Even though Joseph was in a position to allocate generous rations to the members of his family, he did not show them any preference and treated them on the basis of need, each family according to the number of souls. Our sages have stated that at a time when the general population suffers shortage even those who have ample are to limit themselves.

ויכלכל..לחם לפי הטף, the reason children are mentioned is that children eat all day long and waste food, leaving crumbs behind all over the place. Our sages in Pessachim 10 state that it is in the nature of children to break food up into crumbs and to leave them all over the place. There is a well known proverb which states that children are responsible for decay of food.