Schaff, Philip. History of the Christian Church (The Complete Eight Volumes in One). Amazon Kindle Edition, 2014.
Volume 2, Ante-Nicene Christianity A.D. 100-325, “Chapter 8. Christian life in Contrast with Pagan Corruption.” Sections 88-103, Loc. 16158-17158.
§ 101. Prayer and Fasting.
As regards the life of prayer and fasting in early Christianity, Schaff finds the Church in complete unity. All activities would be accompanied by prayer, the strength of every Christian (Schaff 2014, Loc. 17029). At the same time, rather early in Christian history, some fell into the error of thinking prayer actually earned merit before God (Schaff 2014, Loc. 17034). Christians often followed Jewish custom in prayer at dawn, nine, twelve, and three, as well as often at midnight (Schaff 2014, Loc. 17039). Schaff observes that the distinction between prayers “from the heart” and “from memory” is a false dichotomy, as it is quite easy to remember those prayers which are meaningful. He finds the Lord’s Prayer commonly used (Schaff 2014, Loc. 17049). Among the Fathers, posture in prayer was not considered important, but attitude was (Schaff 2014, Loc. 17059).
Because Jews would fast on Monday and Thursday, Christians often fasted on Wednesday and Friday, to set themselves apart (Schaff 2014, Loc. 17064). In the second century, longer fasts before Easter became more common. Schaff also considers the fast or vigil before other important festivals to be an early development (Schaff 2014, Loc. 17064). By the time of the Montanists, legalistic fasting practices were becoming more common. The practice was not only carried on by ascetics but more broadly as well. However, rigorous fasting was countered by those who complained that those fasting despised the good gifts of God.