The twelve small baskets with the leftovers of the feast were carrying-baskets or bags (the word kofinos (κοφίνως) is used in the New Testament only in connection with the feeding of the 5000). Jews often had such little baskets with them (Juvenal mocks that): probably to carry clean food along with them outside of Palestine. They were also part, however, of the travelling outfit of a Roman infantry soldier, who could in this way take along at least three daily rations.1,2
43 And they took up twelve baskets full of broken pieces and of the fish.