This fast is referred to as Great due to both its significance and duration. It is made up of the Quadragesima (forty days) and Passion Week. The Quadragesima was established by the Church in order to observe the forty day fasting and prayer which our Lord kept after His baptism when He was in the desert – before He began His ministry of preaching the gospel. After the holy Quadragesima, which ends on the Friday of the sixth week of Lent, comes the fast of Passion Week, dedicated to our participation in the sufferings and death of our Lord Jesus Christ, according to His command that “the days will come when the bridegroom is taken away from them, and then they will fast...." (Luke 5:35).
It is also referred to as Clean Week for it is during this week – in the hymns and prayers – that we hear the supplication of the soul that repents, cleanses itself, and weeps for its sins. In these stikhera the Church teaches the faithful to turn from the sins in which they have fallen, and not to lose Paradise – through the intemperance of the Foreparents, but – through self-restraint we come to salvation and eternal life. Furthermore, in the services of this week recommended are fasting, prayer, tears, repentance, spiritual struggles, cleansing of the body and soul, a renouncing of sins and vices and accepting the virtue of keeping vigil, - all of this, that we might worthily venerate the Cross and spiritually celebrate the Lord's Resurrection. During this part of the Fast, prayers are longer and more solemn, and more is read rather than sung. The length of the prayers of this week is added by the Great Canon of St. Andrew of Crete served at the Compline on the first four days of Lent. In this, as well as the last week, the fast is significantly stricter, so much so that nothing be eaten on the first two days and, if possible, four days of the fast.