On the Lord's Prayer 19

It can also be understood thus: that we, who have renounced the world and cast away its riches and pomps by the faith of spiritual grace, should ask only for food and sustenance for ourselves, since the Lord instructs us and says: "He who does not renounce all that he has cannot be my disciple." But he who has begun to be Christ's disciple, renouncing all things according to the word of his Master, ought to ask for daily food, and not extend the desires of his petition far ahead, as the Lord again prescribes and says: "Do not think about tomorrow; for tomorrow will think about itself. Sufficient for the day is its own evil." Rightly, then, does Christ's disciple ask for his sustenance for the day, since he is forbidden to think about tomorrow; because it becomes contradictory and inconsistent for us to seek to live long in the world when we ask that the kingdom of God come quickly. So too the blessed apostle warns us, forming and strengthening the firmness of our hope and faith: "We brought nothing into this world, nor can we take anything out. Having, then, sustenance and covering, we are content with these. But those who wish to become rich fall into temptation and snares and many harmful desires, which plunge a man into ruin and destruction. For covetousness is the root of all evils, which some, seeking after, have made shipwreck of the faith and have entangled themselves in many sorrows."