Deuteronomy 8:2-3, 14-16 NRSV
Remember the long way that the Lord your God has led you these forty years in the wilderness, in order to humble you, testing you to know what was in your heart, whether or not you would keep his commandments. He humbled you by letting you hunger, then by feeding you with manna, with which neither you nor your ancestors were acquainted, in order to make you understand that one does not live by bread alone, but by every word that comes from the mouth of the Lord. Do not exalt yourself, forgetting the Lord your God, who brought you out of the land of Egypt, out of the house of slavery, who led you through the great and terrible wilderness, an arid waste-land with poisonous snakes and scorpions. He made water flow for you from flint rock, and fed you in the wilderness with manna that your ancestors did not know, to humble you and to test you, and in the end to do you good.
The bread you give , O God, is Christ’s flesh for the life of the world; the cup of his blood is your covenant for our salvation. Grant that we who worship Christ in this holy mystery may reverence him in the needy of this world by lives poured out for the sake of that kingdom where he lives and reigns with you in the unity of the Holy Spirit, God for ever and ever.
John 6:51-58 NAB
I am the living bread that came down from heaven; whoever eats this bread will live forever; and the bread that I will give is my flesh for the life of the world.” The Jews quarrelled among themselves, saying, “How can this man give us his flesh to eat?” Jesus said to them, “Amen, amen, I say to you, unless you eat the flesh of the Son of Man and drink his blood, you do not have life within you. Whoever eats my flesh and drinks my blood has eternal life, and I will raise him on the last day. For my flesh is true food, and my blood is true drink. Whoever eats my flesh and drinks my blood remains in me and I in him. Just as the living Father sent me and I have life because of the Father, so also the one who feeds on me will have life because of me. This is the bread that came down from heaven. Unlike your ancestors who ate and still died, whoever eats this bread will live forever.”
1 Corinthians 11: 23-29 NRSV
For I received from the Lord what I also handed on to you, that the Lord Jesus on the night when he was betrayed took a loaf of bread, and when he had given thanks, he broke it and said, ‘This is my body that is for you. Do this in remembrance of me.’ In the same way he took the cup also, after supper, saying, ‘This cup is the new covenant in my blood. Do this, as often as you drink it, in remembrance of me.’ For as often as you eat this bread and drink the cup, you proclaim the Lord’s death until he comes. Whoever, therefore, eats the bread or drinks the cup of the Lord in an unworthy manner will be answerable for the body and blood of the Lord. Examine yourselves, and only then eat of the bread and drink of the cup. For all who eat and drink without discerning the body, eat and drink judgement against themselves.