Cyprian of Carthage
Catena Aurea · Matthäusevangelium 6
And when thou prayest, thou shalt not be as the hypocrites are; for they love to pray standing in the synagogues and in the corners of the streets, that they may be seen of men. Verily I say unto you, They have their reward. But thou, when thou prayest, enter into thy closet, and when thou hast shut thy door, pray to thy Father which is in secret; and thy Father which seeth in secret shall reward thee openly.
(Tr. vii. 20.) What insensibility is it to be snatched wandering off by light and profane imaginings, when you are presenting your entreaty to the Lord, as if there were aught else you ought rather to consider than that your converse is with God! How can you claim of God to attend to you, when you do not attend to yourself? This is altogether to make no provision against the enemy; this is when praying to God, to offend God’s Majesty by the neglectfulness of your prayer.