Chapter 33 — Part IV: Prayer — On Prayer in General
Section 4. Therefore, since prayer is necessary to the Christian, the Son of God, yielding to the request of the disciples, Lord, teach us to pray, gave them a prescribed form of prayer, and encouraged them to hope that the objects of their petitions would be granted. He Himself was to them a model of prayer; He not only prayed assiduously, but watched whole nights in prayer.