After the silent prayers of the offertory, the priest prays the prayers of the prelude and the Eucharistic prayer out loud. As a side note, this is a particularly significant change instituted in the Norvus Ordo Mass. Those of a particular age or who have been able to attend an Extraordinary form Mass (sometimes simply called the Latin Mass) know that the Eucharist prayer and many of the other prayers of the Mass are prayed quietly.
The next time that the priest offers a silent prayer is during the singing of the Lamb of God. At this time, the bread and wine have been well and truly consecrated and are now the body and blood of Christ. The priest picks up the primary host and breaks it (often in half). He then breaks off a small piece of the host and deposits it in the wine while praying, “May this mingling of the body and blood of our Lord Jesus Christ bring eternal life to us who receive it.” As a side note, I can tell you that it is a mystical and powerful experience to watch that small piece of the Eucharist slowly absorb the blood, partially because it actually looks a good bit like bloody flesh.
There are a couple of different meanings and significations of this prayer and gesture. The breaking of the host, which Christ himself does at the Last Supper (“He broke the bread and gave it to his disciples…”), signifies the breaking of Christ’s body for our sins. The second part of the gesture is less straightforward. On one hand, the Church embraces the symbolism of the mingling of the body and blood to be a reminder of the Resurrection. While not doctrinal as far as I know, it is commonly thought by theologians and spiritual writers that the actual cause of Christ’s death was exsanguination (basically, total loss of blood).
At the Resurrection, Christ’s body and blood were, in a sense, reunited, and we pray that through the Eucharist which is the Resurrected and reunited body and blood of Christ, we will share in His Resurrection and eternal life. It is very important for us to realize that the body and blood of Christ that we receive is not the dead body of Christ on the cross. It is His Resurrected body, living even now. Because He lives, we receive His vitality, His life, His blood, soul, and divinity through His body, not dead, lifeless matter.
Another origin for the mingling of a particle of the host in the chalice was the spirit of ecclesial unity. In Masses of ages past, a particle from the consecrated host at the bishop’s Mass called a fermentum was brought to the parish church and mingled in the priest’s chalice as a sign of the unity of the priest’s Mass with the bishop’s. With this unity in mind, the priest’s prayer during the ritual action of commingling can take on other dimensions. The particle from the bishop connects the Mass with the whole diocesan Church, and the prayer can serve an intercessory role for all those in the diocese who receive from the bishop’s host. It also reminds us that salvation is not a solitary affair but, like Holy Communion, it is something that we strive for together and that brings us into unity even as it also has a dramatically personal dimension. Seen under the sign of unity, the co-mingling reminds us that receiving the Eucharist is certainly entering into communion with Christ, but it is also deepening our communion with his Bride, the Church.
Following this prayer and gesture, the priest then offers a silent, personal, and intimate prayer to prepare himself to receive communion.
There are two options for this prayer and both are somewhat lengthy, so I will not include them here. Both options focus on humility, on praying for spiritual strength, and unity with God. The congregation can tell when the priest finishes this prayer because he immediately genuflects upon its completion.
Directly before receiving the body and blood of Christ, the priest whispers, “May the body/blood of Christ keep me safe for eternal life.”
After communion, the priest or deacon uses water to consolidate and consume the leftover particles of the Eucharist that remain in the vessels. Directly before consuming the water, he whispers the final silent prayer of the Mass, “What has passed our lips as food, Oh Lord, may we possess in purity of heart, that what has been given to us in time may be our healing for eternity.” Here, at the final moment of the Eucharist meal, the priest is offering one final prayer of intercession for all. Essentially, the priest is praying that we may maintain purity as we go forth, united to the Eucharist. Sometimes, directly after Mass, it is easy to forget the momentous gift that is in/with/united to us and we go forth as if everything is the same. But we should go forth seeking to live purely and to maintain our bodies as Sacred temples of the God we just received. Furthermore, the priest prays that this individual reception of the Eucharist may have real consequences in an on-going way all the way through eternal life.