Catechism of the Catholic Church
Before so great a sacrament, the faithful can only echo humbly and with ardent faith the words of the Centurion: “”Domine, non sum dignus ut intres sub tectum meum, sed tantum dic verbo, et sanabitur anima mea”” (“”Lord, I am not worthy that you should enter under my roof, but only say the word and my soul will be healed.””), and in the Divine Liturgy of St. John Chrysostom the faithful pray in the same spirit: O Son of God, bring me into communion today with your mystical supper. I shall not tell your enemies the secret, nor kiss you with Judas’ kiss. But like the good thief I cry, “Jesus, remember me when you come into your kingdom.”
Source: Catechism of the Catholic Church #1386