Leo the Great, a native of Tuscany, was elected bishop of Rome in 440 and is perhaps best known for meeting with Attila the Hun in 452 and persuading him to turn back from his invasion of Italy.  The nearly 100 sermons and 150 letters of his that have survived are mostly concerned with theological questions concerning the person of Jesus Christ and his role as Mediator and Saviour.  Leo taught extensively on Christ's presence in the Church: in the teaching of Scripture, in the preaching of the faith, in the liturgy and in the life of the individual believer.

The Lord then goes on to say: Blessed are those who hunger and thirst for righteousness, for they shall be filled. This hunger is not for any bodily food, this thirst is not for any earthly drink: it is a longing to be blessed with righteousness, and by penetrating the secret of all mysteries, to be filled with the Lord himself.