The events of the next three days—the crucifixion, entombment, and resurrection—represent the central focal point of all of human history. For all of prior history culminates in the empty tomb. And all subsequent events are eternally changed by it. It is ultimately a mystery, one which Jesus knows his friends will not begin to understand until much later.
And so, reclined at the table where they are eating, he takes the bread and lifts it for all to see. He says a prayer of thanks. He breaks it in portions to share. And then, he says, "take and eat; this is my body." [Matt 26:26 TNIV]