Thanks for providing the text, PP. The prayers show many similarities with the Lord's Prayer, the Kiddush, and the Amidah, and the petition on behalf of the church is also reminiscent of the Qumran Hoyadot. It thus stands much closer to traditional Jewish thanksgiving than the Eucharist given in 1 Corinthians, Luke, and the Eucharistic interpolations found in John (as well as allusions to the Eucharist in Ignatius of Antioch, Romans 7:3; Smyrnaeans 6:2; Philadelphians 4:1; Justin Martyr, 1 Apology 66.3) which come right out of Mithraism:
"I tell you the truth, unless you eat the flesh of the Son of Man and drink his blood, you have no life in you.... Whoever eats my flesh and drinks my blood has eternal life, and I will raise him up at the last day" (John 6:53-54)."He who will not eat of my body, nor drink of my blood so that he may be one with me and I with him, shall not be saved" (Mithraic Prayer, pre-Christian inscription found in the Vatican, Rome)
According to JD Crossan, the general Eucharistic prayer in Didache 10 is older than the prayers in ch. 9 which ritualize the bread and the wine, but even in the latter there is no reference to the death of Jesus, a Last Supper with his followers, or passion symbolism of broken body and blood. This also fits well with the Didache's provenience in Nazarene communities in Syria (among whom the Passion lacked the significance it had with Pauline Christians) and literary kinship with Q, which like the Gospel of Thomas also lacked a Passion narrative. Thus the wine in Didache 9:2 had nothing to do with the blood of Christ poured out on the cross, but simply meant that Jesus is of the "vine of David", i.e. the Messiah. Moreover, it is thought that the present form of the verse contains a duplication of paidos sou "your servant" which is absent in the paralleled prayer regarding the bread and which obscures the sense of Jesus revealing the "vine of David"; the original text would have read thus: "We give you thanks, our Father, for the holy vine of David, which you have made known to us through Jesus your servant, to you be the glory forever". Since the "vine" is used as a metaphor for the kingdom in Q, Mark, and the Gospel of Thomas (cf. Mark 12:1-12; Matthew 20:1-16, 21:28-46; Luke 20:9-19; Gospel of Thomas 65), which is being given to the disciples as their inheritance, and since "vine" is a traditional symbol of Israel and the restored Messianic kingdom in Psalm 80:8-18; Isaiah 5:1-7; Jeremiah 2:21, the allusion in the Didache prayer would seem to be to the kingdom which Jesus revealed (which is also the dominant theme in Q). Likewise the bread of the Eucharistic meal did not symbolize Jesus' sacrificial flesh but rather indicated the "life and knowledge which you made known to us through Jesus your servant" (Didache 9:3), drawing on the same bread=knowledge/life and wheat=gospel metaphors we see in Mark 2:25-26, 4:14-20, 6:30-44; Matthew 4:4. The following verse goes on the extend the symbolism to the church, symbolizing the way wheat which had been "scattered upon the mountains" and then formed into the unity of a loaf of bread, so the church likewise is "gathered together from the ends of the earth into your kingdom" (Didache 9:4). The Eucharist ritual of early Jewish-Christians was thus one that centered on the coming eschatological kingdom (cf. 10:6), and the communial drinking of the wine and the distribution and consumption of the bread symbolized the "life and knowledge" of the kingdom that is being shared among all those in the church: "We give you thanks, Holy Father, ... for the knowledge and faith and immortality which you have made known to us through Jesus your servant ... to us you have graciously given spiritual food and drink, and eternal life through your servant" (10:2-3).
Very different from the Mithraic-type formulae of Paul and the Last Supper narrative of Luke, though the focus on salvation is common to both. However, Luke might preserve a fragment of the original proto-Markan account of the Last Supper, for there are actually two separate utterances about the wine, one given before the bread and one given after (Luke 14:17-18, 20), and while the second is reproduced in 1 Corinthians 11:25, the first has no direct parallel in Paul: "And he took a cup, and when he had given thanks he said, 'Take this, and divide it among yourselves; for I tell you that from now on I will not drink of the fruit of the vine until the kingdom of God comes' " (14:17-18). If we recognize this as part of the earliest strata of the Last Supper narrative, we can readily see that each of the individual gospels has interpolated the Pauline material in different places: In Mark (= Secret Mark redaction?), the Pauline formula about "my blood of the covenant" is inserted after the disciples drank the wine (Mark 14:22-25), in Matthew the Pauline formula is inserted into Jesus' command to drink from the wine, while he was distributing it to his disciples (Matthew 26:26-29), and in Luke the Pauline formula is inserted after both the first cup and bread, as an "after-supper" cup (in agreement with 1 Corinthians 11:25). In all three gospel accounts (after removing the anomalous Pauline formula), the utterance about drinking the "fruit of the vine" occurs just after Jesus "giving thanks" over the cup (Mark 14:23; Matthew 26:27; Luke 22:17), which would be expected if it constitutes the earliest layer to the Last Supper narrative. Moreover, it is echoed in a positive form by Paul who says "whenever you eat this bread and drink this cup, you proclaim the Lord's death until he comes" (1 Corinthians 11:26), suggesting a more primitive version of the text in Luke 14:17-18 that refers to Christians drinking from the Eucharist cup in anticipation of the eschatological kingdom, e.g. "May you drink from the fruit of the vine of David and proclaim the kingdom of God until it comes", which was then adapted in different ways by Paul and Luke (and also Mark and Matthew) to refer to Jesus' death instead of the kingdom. The references to the "fruit of the vine" and the "kingdom of God" in Luke 14:17-18 are two literary features that link the passage with the Didache prayer which also likely associates the vine itself with the kingdom.