Just as someone who goes to meet somebody stands in the road and awaits him until he comes, so he who believes in Christ ought to live in this age as a pilgrim and be situated not at home but in a passageway. For this reason, when the Jews were also about to leave Egypt, they were ordered to eat the lamb ready and with their loins girded and prepared to leave, thus showing us how whoever eats the Eucharist of our lamb ought also to be ready in this way as if they were daily departing from the world.
Incomplete Commentary on Matthew, c. 400 A.D.
Locus Communis 