On this last Sunday before Great Lent, the last day that traditionally Orthodox Christians eat dairy products until Easter, the Church remembers the expulsion of Adam and Eve from Paradise. God commanded them to fast from the fruit of a tree (Gen. 2:16), but they did not obey. In this way Adam and Eve and their descendants became heirs of death and corruption.
After the dismissal at Vespers, The priest stands beside the analogion, or before the ambon, and the faithful come up one by one and venerate the ikon, after which each makes a prostration before the priest, saying “Forgive me, a sinner.” The priest also makes a prostration before each “God forgives. Forgive me.” The person responds, “God forgives” and receives a blessing from the priest. Meanwhile the choir sings quietly the Irmoi of the Paschal Canon, or else the Paschal Stichera. After receiving the priests blessing, the faithful also ask forgiveness of each other.
Kontakion (Tone 6)
Master, Teacher of wisdom,
Bestower of virtue,
You teach the thoughtless and protect the poor:
Strengthen and enlighten my heart.
Word of the Father,
Let me not restrain my mouth from crying to you:
Have mercy on me, a transgressor,
O merciful Lord!
From www.orthodoxwiki.com