Mazza, Enrico. "Chapter Seven: Thematic Developments in the Eucharistic Liturgy." The Celebration of the Eucharist: The Origin of the Rite and the Development of Its Interpretation. Collegeville, MN: The Liturgical Press/Pueblo, 1999, 75-92.
Mazza evaluates ways in which eucharistic concepts may have developed as evidenced in various documents. He begins with the thanksgivings in Didache 9 and 10. In chapter nine, the typical Jewish thanksgiving for the "fruit of the vine" is expanded to the vine of David (Mazza 1999, 75). Mazza doesn't find a definite reference to Jesus' presence here. It may speak rather of the history of salvation made available in Israel's history (Mazza 1999, 76). Here, the stated "object of the thanksgiving is the 'holy Name' of God which he has 'made to dwell in our hearts;" (Mazza 1999, 77). Mazza considers that this may refer to God's presence in His people, but here not in the temple but in some other way (Mazza 1999, 78). God is present in the hearts of His people.
The thanksgiving in Didache 10.5 contains a petition which Mazza considers similar to the Birkat ha-Mazon. In the Jewish prayer the thanksgiving is for Israel, while the form in the Didache is focused on the Church (Mazza 1999, 78). While the content differs, Mazza sees a conceptual similarity, as the prayers both give thanks to God for the places and people central to the context of worship. There is also a prominent theme of a gathering, which Mazza finds also in Sirach 36:10-14 (Mazza 1999, 79).
Mazza goes on to describe Paul's use of eucharistic liturgy as evidenced in 1 Corinthians 10-11. "Paul conceives of the Eucharist as a sacrament of unity" (Mazza 1999, 81). This, as well as the concept of God's people being scattered, then gathered, may well be derived from Old Testament passages such as Jeremiah 37-38, where bad shepherds scatter God's sheep (Mazza 1999, 81). In passages such as Ezekiel 34, Isaiah 60, Isaiah 66, and Isaiah 27 God gathers his people together. They are brought firmly into an internal covenant in Jeremiah 39 (Mazza 1999, 82). The gathering of God's people is, therefore, an important Old Testament concept. Paul's development, which Mazza considers the last of important developments in the eucharist, is that "unity is connected with the sacramental nature and the efficacy of the Eucharist" (Mazza 1999, 83-84). God's people, gathered as one body, eat one bread. The eucharistic celebration actually serves to create unity, not merely to symbolize it (Mazza 1999, 85).
Mazza observes a connection between Didache 9-10 and John's Gospel though he freely admits there is no evidence to show the Didache as dependent on John (Mazza 1999, 86). Both come from a similar early Christian tradition. Mazza considers the theme of God drawing people into unity as the link between the two works (Mazza 1999, 87).
The "Mystical Eucharist" from book seven of Apostolic Constitutions shows a strong correspondence to the eucharist as described in the Didache (Mazza 1999, 88). Mazza considers the few distinctions between the two texts as important, so he addresses them in turn. The prayer for unity takes on what Mazza considers a Pauline emphasis on "us" rather than on "the Church" (Mazza 1999, 89). Christ is seen as a mediator of salvation, sent by the Father. The Words of Institution are also present, though absent from the Didache (Mazza 1999, 90). This signals an awareness of a sacramental function of the material, purposely handed down as a typological event.