[sorry this is so tardy --- for some reason my computer and browser have not been playing well with others the past few days. For the same reason, the St. Justin quotation will be from a different translation than that used in the LofH books, since the LofH sites have already cleared Sunday....]
In this Sunday's gospel reading, two people were walking home from Jerusalem. Faces down, distraught, disillusioned, in mourning. (The easterners say that this was St. Cloepas and somebody. Maybe his wife? We know from the gospels that she was one of the disciples from early on, and was at the crucifixion.) Somebody else walking the same direction met them on the road. Somebody they knew very well indeed. They walked with this fellow-traveller and conversed all afternoon and did not recognise Him.
Did they even really see Him? Mourning and dejection don't do a whole lot for one's perceptiveness, I know this from experience. The text says their faces were lowered and their eyes downcast. But they did the right thing and the only societally proper thing, and offered their fellow-traveller hospitality in their home, since it was too late in the afternoon to make it to the next town before dark. And when they sat down to supper, the unknown one took the bread, said the blessing, broke the bread and gave it to them [you may want to check in Luke and Acts when Luke uses these terms instead of "they ate" or "they were fed"......] and they recognised them in the breaking of the bread. For the first time all afternoon, they actually saw Him. And He left them, disappeared from their sight. (and, only a few minutes later, walked through the locked door of a certain upper room not far from His mom's apartment in Jerusalem; oh, the wonders of a glorified resurrection body!)
We also, even to this very day and onward to the end of the age, have troubles seeing Him sometimes, though He is among us, yet we recognise Him in the breaking of the bread. Every time we celebrate the Eucharist and partake of the one Body of Christ, and of the one cup of blessing of the Blood of Christ, we become what we receive, and we recognise Him.
Back in the 100s, St. Justin wrote about how the Christians celebrated the Holy Eucharist, and he describes the same six movements in which we have celebrated the Holy Eucharistic Liturgy in every generation continuously until now, making the one death and the one resurrection of our Lord and Messiah continually now for us. Recall that it is the evil child who says "the Lord delivered our ancestors from Egypt" --- only them back then, not us --- and the good and wise children who proclaim "I have been brought out of the house of bondage".
Here are St. Justin's words, which were the appointed reading for this past Sunday's Office of Readings:
And this food is called among us the Eucharist, of which no one is allowed to partake but the man who believes that the things which we teach are true, and who has been washed with the washing that is for the remission of sins, and unto regeneration, and who is so living as Christ has enjoined. For not as common bread and common drink do we receive these; but in like manner as Jesus Christ our Saviour, having been made flesh by the Word of God, had both flesh and blood for our salvation, so likewise have we been taught that the food which is blessed by the prayer of His word, and from which our blood and flesh by transmutation are nourished, is the flesh and blood of that Jesus who was made flesh. For the apostles, in the memoirs composed by them, which are called Gospels, have thus delivered unto us what was enjoined upon them; that Jesus took bread, and when He had given thanks, said, "This do ye in remembrance of Me, this is My body;" and that, after the same manner, having taken the cup and given thanks, He said, "This is My blood;" and gave it to them alone. Which the wicked devils have imitated in the mysteries of Mithras, commanding the same thing to be done. For, that bread and a cup of water are placed with certain incantations in the mystic rites of one who is being initiated, you either know or can learn.
And we afterwards continually remind each other of these things. And the wealthy among us help the needy; and we always keep together; and for all things wherewith we are supplied, we bless the Maker of all through His Son Jesus Christ, and through the Holy Ghost. And on the day called Sunday, all who live in cities or in the country gather together to one place, and the memoirs of the apostles or the writings of the prophets are read, as long as time permits; then, when the reader has ceased, the president verbally instructs, and exhorts to the imitation of these good things. Then we all rise together and pray, and, as we before said, when our prayer is ended, bread and wine and water are brought, and the president in like manner offers prayers and thanksgivings, according to his ability, and the people assent, saying Amen; and there is a distribution to each, and a participation of that over which thanks have been given, and to those who are absent a portion is sent by the deacons. And they who are well to do, and willing, give what each thinks fit; and what is collected is deposited with the president, who succours the orphans and widows and those who, through sickness or any other cause, are in want, and those who are in bonds and the strangers sojourning among us, and in a word takes care of all who are in need. But Sunday is the day on which we all hold our common assembly, because it is the first day on which God, having wrought a change in the darkness and matter, made the world; and Jesus Christ our Saviour on the same day rose from the dead. For He was crucified on the day before that of Saturn (Saturday); and on the day after that of Saturn, which is the day of the Sun, having appeared to His apostles and disciples, He taught them these things, which we have submitted to you also for your consideration.
[First Apology, chapters 66-67]