The man will show you a large upper room furnished with couches. Make the preparations there. They set off and found everything as he had told them and prepared the Passover. (Lk. 22,12-13)

This is the part of the house He chose to share the last dinner with his disciples. This time it was different because it was a farewell dinner. First Christians knew that house and the room and venerated the place since the first years of Christianity. Churches and Sanctuaries were built in memory of this event.
Step up and see the place where the Lord had constituted the Eucharist and where he gave his disciples the example of being their master by washing their feet. This is the place where they gathered after the Ascension of the Lord. The place where they elected Matthias instead of Judas and the place where they received the Holy Spirit on the day of Pentecost. This is the place where the Mother Church of Jerusalem was founded. So step out from this room and, as the disciples did, preach loudly the world of the Lord with no fear.