Writing in Greek, Matthew, Mark, Luke and Paul gave us direct accounts of what Jesus said over the bread and wine at the Last Supper. If we directly translate their words into English, we see that Jesus, speaking in the Present Tense, said, "This is my body which is for you," and, "This is my blood this is poured out for you."
However, our Church, both in its English version of the New Testament, and in the word given the priest to speak at Mass, switches the tense of Our Lord's words, having him say. "This is my body which will be for you," and "This is my blood which will be poured out for you."
Th Church makes those changes to accent the part Christ's death on the cross makes in the sacrificial death offered for us. However, if we allow Our Lord's to remain as they were in the New Testament accounts of them, we would be seeing his commitment to a sacrificial death as having been initiated at the Last Supper.
Our Lord's table blessing at the Last Supper had three part to it. First, he asked the disciples to join with him in thinking God for his favors; secondly he made them aware of their being in conversation with God; thirdly he asked them to be physically and mentally one with him as a pleasing gift, one Eucharist, offered to the Father.