Here’s how this works:
Christ instructs what is to be done;
Mathew 26:26-28
Now as they were eating, Jesus took bread, and blessed, and broke it, ad gave t to the disciples and said, Take, eat; this is my body.
And he took a chalice, and when he had given thanks he gave it to them saying, Drink of it, all of you; for this is my blood of the covenant, which is poured out for many for the forgiveness of sins.
And THEN He tells us to repeat this in remembrance of Him.