“Behold the Lamb of God who takes away the sin of the world.”
These familiar words from the liturgy of the mass, said when the priest breaks the host just before communion, are actually taken from John the Baptist, pointing out Jesus in today’s gospel. The breaking of the host symbolizes Jesus offering himself as lambs were offered as sin-offerings in sacrifice at the temple of Jerusalem. The reference to Jesus as the Lamb of God is an echo of Isaiah’s prophecy in chapter 53, verses 7 and 10 speaking about the “servant of the Lord” who is led to his death like a lamb led to slaughter. In Isaiah the death of the servant is seen as the ultimate offering to take away the sins of mankind. Christians have always seen Jesus’ death on the cross as being an exact fulfilment of the words of Isaiah’s prophecy.
The reference to Jesus being the “Lamb of God” may also be a reference to the Passover lamb. In Exodus 12, just before God is about to strike down the first born sons of the Egyptians, to force the Pharaoh to allow the Israelites to go free from their slavery and journey to the Promised Land, Moses is told to instruct the people to Israel to sacrifice a lamb “without blemish.” The blood of the lamb was to be sprinkled around the threshold of the Israelites’ homes, so that the angel of destruction, seeing the blood, would “pass over” the home and not strike down the first born son. Jesus is seen as that lamb, whose blood shed at Calvary, would deliver us from the penalty of hell, because it would wash away our sins. In John’s gospel, Jesus actually dies at the very hour (3pm) when the lambs for the Passover would be sacrificed by the priests at the Temple. After that, the cry would be proclaimed throughout the Temple “no more lambs to be sacrificed,” i.e. after 3pm. Jesus’ words on the cross as he dies “It is finished” is a deeper fulfilment of that proclamation, meaning no more sacrifices for sin need to be made, because Jesus, by his death, has made the once-for-all sacrifice for sin. St Peter in his first letter (1:19) expresses all this succinctly when he writes: “we were ransomed from our sin with the precious blood of Jesus as a spotless unblemished lamb.”
All of this rich imagery from the Old Testament is called to mind, then, when the priests elevates the host during Mass and proclaims the words “Behold the Lamb of God who takes away the sins of the world.”