The disciples did not yet understand about Calvary. It had not happened at the time the Supper was instituted.
What we do when we read the Scriptures and pray and bow our heads in private prayer, taking the elements? We give thanks. O with all our hearts we give thanks to God. It is a thanksgiving ordinance. We thank him for salvation. We thank him for Christ. We thank him for his broken body. We thank him for his patience with us; for all that he has done for us. We praise him and thank him for the church, for the fellowship of God’s people. He sacrificed himself for us. What have we done for him? What small return, what poor return have we made?
Is it really the body of Christ? Of course not. It is a symbol of the body of Christ, and it is distributed and we take it and eat it. It represents Christ’s body broken for us and Christ said this, holding it up: this is my body, meaning it represents my body, which is broken for you.