In the Orthodox Church, the last Sunday before Great Lent—the day on which, at Vespers, Lent is liturgically announced and inaugurated—is called Forgiveness Sunday. On the morning of that Sunday, at the Divine Liturgy, we hear the words of Christ:
“If you forgive men their trespasses, your heavenly Father will also forgive you, but if you forgive not men their trespasses, neither will your Father forgive your trespasses…” (Mark 6:14-15)…more to read from Father Alexander Schmemann at: https://www.oca.org/saints/lives/2023/02/27/8-beginning-of-great-lent