The celebration of the Eucharist ends simply with a blessing and a dismissal. The blessing by the presiding priest or bishop stands as an excellent example of how the liturgy with its various parts has not been handed down to us through the centuries unchanged. The fundamental actions of the liturgy - taking and blessing bread and wine, breaking the bread and pouring the wine, and distributing this eucharistic food to the people - have remained the same. But many other parts of the Mass have a varied and complex history, emerging and developing in different ways in different places.
In the city of Rome the first form of a blessing at the end of the liturgy seems to have been an admonition from the deacon to bow before the Lord, followed by a “prayer over the people” prayed by the bishop. From the sixth century this blessing was restricted to the season of Lent, perhaps as a blessing reserved for penitents who were preparing in this season for the reconciliation with the Church on Holy Thursday. From the late seventh century an additional and more simple form of blessing began to emerge, as the pope began silently blessing each section of the assembly as he left the church. Though originally reserved only to the pope, from the eleventh century many parish priests also gave this simple form of concluding blessing.
Gradually there emerged a ritual difference between the blessing imparted by a priest or by a bishop. A bishop would make the sign of the cross with his hand, while the priest would use some blessed object. Sometimes the object would be a relic of a holy person or a relic of the cross of Jesus. Since the fourteenth century, particularly in France and Germany, it became customary for priests to hold a crucifix, or the plate or even the cloth upon which the consecrated bread had been placed during the liturgy. These practices have long since disappeared. Today the blessing is imparted prior to the dismissal and before the priest or bishop leaves the church. A priest blesses the assembly with one simple sign of the cross, and a bishop offers the blessing with a slightly longer formula and with three signs of the cross. On special occasions both priest or bishop may use a somewhat more solemn formula of blessing.
Of course it is important to focus, not upon the details of historical development, but on the nature of the blessing as a prayer of the Church assembled in prayer. To bless a person means to use a set of words and actions as a request that God continue to bestow divine generosity. The final blessing at the end of the liturgy asks that the greatest of all benefits may be given in abundant measure to the people present who have shared in God’s word and partaken in the gift of Christ’s body and blood. Such a blessing at a time of departure is actually quite common, even outside the liturgy, for the familiar “goodbye” we offer to others is really a shortened form of the blessing “God be with you.” Nor can we forget the touching scene found in Luke’s gospel. Before leaving his followers for the final time, and before being taken up into heaven, “with hands upraised, he blessed” the apostles.