Cosmas and Damian are two of the martyrs included in the ancient Roman Canon (Eucharistic Prayer I). Prayer before the Consecration:
In communion with those whose memory we venerate, especially the glorious ever-Virgin Mary, Mother of our God and Lord, Jesus Christ, + and blessed Joseph, her Spouse, your blessed Apostles and Martyrs, Peter and Paul, Andrew, (James, John, Thomas, James, Philip, Bartholomew, Matthew, Simon and Jude; Linus, Cletus, Clement, Sixtus, Cornelius, Cyprian, Lawrence, Chrysogonus, John and Paul, Cosmas and Damian) and all your saints; we ask that through their merits and prayers, in all things we may be defended by your protecting help. (Through Christ our Lord. Amen.)
"It is beautiful to think that although we hardly know anything of these saints' lives on earth, we are forever recalling these glorious martyrs at the Supper of the Lamb. While we may not have intimate portrayals of their human lives, we do know these saints very intimately. How can we not, when you are together at the heavenly meal every week? Sharing meals together, seated around the same table provides closeness and intimacy, and that is what we are doing together at every Mass. They are part of our family, and the witnesses of the Heavenly Banquet "who had been slain for the Word of God and for the witness they had borne" (Rev. 6:9). This excerpt from the Dogmatic Constitution of the Church reinforce this view of the Liturgy and our connection with the martyrs:
Our union with the Church in heaven is put into effect in its noblest manner especially in the sacred Liturgy, wherein the power of the Holy Spirit acts upon us through sacramental signs. Then, with combined rejoicing we celebrate together the praise of the divine majesty; then all those from every tribe and tongue and people and nation who have been redeemed by the blood of Christ and gathered together into one Church, with one song of praise magnify the one and triune God. Celebrating the Eucharistic sacrifice therefore, we are most closely united to the Church in heaven in communion with and venerating the memory first of all of the glorious ever-Virgin Mary, of Blessed Joseph and the blessed apostles and martyrs and of all the saints (Lumen Gentium, 50d).
It is through the blood of the martyrs that the Church expanded and continues to grow. What a blessing to have this intimate connection with the roll call of martyrs at the Roman Canon. We are continually reminded of belonging and participating in the family of Christ. Let us remember to invoke these blessed martyrs today, and all the saints of the Canon so that in our death we may join our brothers and sisters in the Heavenly Supper of the Lamb."
Excerpt from Cosmas, Damian and Saints of the Canon by Jennifer Gregory Miller 26 Sept 2014. Full text: Click here: Cosmas, Damian and Saints of the Canon | Catholic Culture