A subdeacon must not give the Bread, nor bless the Cup.
Ancient Epitome of Canon XXV.
A subdeacon may not give the bread and the cup.
Subdeacons are not allowed to perform the work of presbyters and deacons. Wherefore they neither deliver the bread nor the cup to the people.
According to the Apostolic Constitutions, the communion was administered in the following manner: the bishop gave to each the holy bread with the words: “the Body of the Lord,” and the recipient said, “Amen.” The deacon then gave the chalice with the words: “the Blood of Christ, the chalice of life,” and the recipient again answered, “Amen.” This giving of the chalice with the words: “the Blood of Christ,” etc., is called in the canon of Laodicea a “blessing” (εὐλογεῖν). The Greek commentator Aristenus in accordance with this, and quite rightly, gives the meaning of this canon.
This canon is found in the Corpus Juris Canonici, Gratians Decretum, Pars I., Diet. XCIII., c. xix.; but reads “Deacons” instead of “Subdeacons.” The Roman Correctors point out the error.