From the Lenten Triodion:
Tuesday of The First Week
Let us begin the pure fast, O people, which is the salvation of our souls. Let us serve the Lord with fear; let us anoint our heads with the oil of good deeds. Let us wash our faces with waters of purity. Let us not use empty phrases in prayer, but as we have been taught, let us cry out: Our Father in Heaven, forgive us our trespasses, for you are the lover of mankind.
(Matins Apostika)