Why do priests drop a piece of host into the chalice? If you have been paying attention at Mass, you will notice the priest breaks a small piece of the consecrated host and drop it into the chalice. This ritual is one of those things that happens silently and quickly that a lot of people miss.
Even though this might seem like an insignificant tradition, the truth is the symbolism behind this is quite profound.
Unity to the Hierarchy
Participation in the same Holy Sacrifice was regarded as a sign and pledge of ecclesiastical Communion; mutually to prove and maintain this, Popes and bishops sent to other bishops, or priests too, parts of Consecrated Hosts, which the recipients dropped into the chalice and consumed. This custom existed in Rome until about the ninth century. There the Pope on Sundays and feast-days sent to those priests who had charge of Divine service at the churches within the city, the Eucharist as a symbol of Communion with the ecclesiastical Head, and as a sign that they were empowered to celebrate.Nikolaus Gihr, The Holy Sacrifice of the Mass
This ritual reminds the celebrant they are united to the bishop and the Pope. This interpretation makes sense since the Pope personally approves the ordination of every bishop in the world, and the latter himself ordains his priest; Holy Order flows from the Head to every member of the Church. Everyone ordained in the Church receives Holy Orders from the Apostles, and the Pope is the Head.
The One Sacrifice
Also, the ritual signified the unity of the celebration of Mass. We believe the Mass is a reenactment of the one Sacrifice of Jesus on the cross. Jesus is not dying, again and again, each time we celebrate Mass. However, the Eucharist is mystical participation in that same Sacrifice that occurred at Calvary.
We believe that God is above time and space. He can apply the merits of the Sacrifice of Jesus before and after its historical occurrence.
Formerly the usage was somewhat different. As the Hosts were much larger, one of these three parts was subdivided into several particles and used differently, that is, distributed to those present, or sent to the absent, or put into the chalice at the next sacrificial celebration… A particle previously consecrated was preserved and united to the Precious Blood at the following Sacrifice to represent, in all probability, the continual succession of the Sacrifice, as well as the unity of the last with the present celebration.Nikolaus Gihr, The Holy Sacrifice of the Mass
This was the reason many believed that for a few centuries, the practice was to put two pieces in the chalice instead of one. One from the pope/bishop and another from a previous celebration.
This ritual also points to the unity of the body and blood of Jesus in the host because both host and wine contain the whole presence of Jesus after consecration: body, blood, soul, and divinity.
The Mass manifests years of witnessing by the faithful bride of Christ, the Church. Each participant should remember to participate in:
“giving thanks that you have held us worthy to be in your presence and minister to you.”
Why do priests drop a piece of host into the chalice?