On Wednesday evening a very special service is celebrated in Orthodox churches—the Great Canon with the Life of St. Mary of Egypt. This is the only time in the year when the Great Canon of St. Andrew of Crete, which was read in four parts during the first week of Great Lent, is read in its entirety, along with the canon to St. Mary of Egypt. This canon contains every motivation toward fasting and repentance, and the Church repeats it in the fifth week in its entirety in order to inspire us with renewed strength to finish the course of the fast. The Life of St. Mary of Egypt is also read to that end—to motivate us to be attentive and repent.
During the Matins service for Thursday (read on Wednesday evening), the first half of the Life of St. Mary of Egypt is read following sessional hymns after the kathisma (Psalter reading). Then we read Pslam 50, and begin the Great Canon. The second part of the Life of St. Mary is read after the third ode of the Canon.