Catechism of the Catholic Church
“The first announcement of the Eucharist divided the disciples, just as the announcement of the Passion scandalized them: ‘This is a hard saying; who can listen to it?’ The Eucharist and the Cross are stumbling blocks. It is the same mystery and it never ceases to be an occasion of division. ‘Will you also go away?’ The Lord’s question echoes through the ages, as a loving invitation to discover that only he has ‘the words of eternal life’ and that to receive in faith the gift of his Eucharist is to receive the Lord himself.”
Source: Catechism of the Catholic Church #1336