Word and Eucharist

"The Eucharist is light above all because at every Mass the liturgy of the Word of God precedes the liturgy of the Eucharist in the unity of the two 'tables': the table of the Word and the table of the Bread. This continuity is expressed in the Eucharistic discourse of Saint John's Gospel, where Jesus begins his teaching by speaking of the mystery of his person and then goes on to draw out its Eucharistic dimension: 'My flesh is food indeed, and my blood is drink indeed' (John 6:55). We know that this was troubling for most of his listeners, which led Peter to express the faith of the other Apostles and of the Church throughout history: 'Lord, to whom can we go? You have the words of eternal life' (John 6:68). In the account of the disciples on the road to Emmaus, Christ himself intervenes to show, 'beginning with Moses and all the prophets,' how 'all the Scriptures' point to the mystery of his person (cf. Luke 24:27). His words make the hearts of the disciples 'burn' within them, drawing them out of the darkness of sorrow and despair, and awakening in them a desire to remain with him: 'Stay with us, Lord' (cf. v. 29)."
John Paul II, Apostolic Letter Mane nobiscum Domine, 12