Evening, and morning, and at noon will I pray, and cry aloud: and he shall hear my voice.
Let us who are in Christ—who are always in the light—not stop praying even at night. The widow Anna never stopped praying and watching, but persevered in pleasing God. As it is written in the Gospel of Luke, "She departed not from the temple, serving with fastings and prayers night and day."...Beloved, who are always in the light of the Lord, consider night the day. Believe that we always walk in the light, and don't be hindered by the darkness we have escaped from. Don't fail to pray in the night hours...You who are newly created and newborn by the Spirit through God's mercy, imitate what we will be someday. Since in the kingdom of heaven we will only have day without night, keep watch at the night as you would in daylight. Since we are going to pray and give thanks to God forever, let us not stop praying and giving thanks in this life also.
—Cyprian, Treatise 4 (as found in Day by Day with the Early Church Fathers: Selected Readings for Daily Reflection)