The Didache tells Christians to gather on the Lord’s Day, break bread, give thanks, and reconcile so that their ‘sacrifice may be pure’ (Didache 14). Irenaeus applies Malachi’s prophecy of a pure offering among the nations to the Church and calls its oblation a pure sacrifice (Against Heresies 4.17–18). Cyril of Jerusalem describes the Eucharistic liturgy as a spiritual sacrifice and bloodless service (Catechetical Lecture 23).
Patristic sacrificial language is not a denial of the Letter to the Hebrews or a claim that Christ must be crucified again. The Church offers thanksgiving, created gifts, prayer, and the sacramental memorial of the one saving sacrifice. The exact conceptual vocabulary develops, but calling the Eucharist ‘not a sacrifice in any sense’ does not fit the early sources.
Primary sources
Didache 14: https://www.newadvent.org/fathers/0714.htm
Irenaeus, Against Heresies 4.17–18: https://www.newadvent.org/fathers/0103417.htm
Cyril, Catechetical Lecture 23: https://www.newadvent.org/fathers/310123.htm