Augustine of Hippo
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.
(ubi sup.) Or, by our chambers are to be understood our hearts, of which it is spoken in the fourth Psalm; (Ps 4:4.) What things ye utter in your hearts, and wherewith ye are pricked in your chambers. The door is the bodily senses; without are all worldly things, which, enter into our thoughts through the senses, and that crowd of vain imaginings which beset us in prayer.