The Guide of wisdom, Leader of prudence, Chastener of the senseless, and the Defender of the poor: fortify, grant understanding to my heart, O Master. Give me a word, O Word of the Father, for behold, I do not hold back my lips from crying out to You: O Merciful, have mercy on the fallen.
Adam sat and wept across from the delight of Paradise, and beating his eyes with his hands, he said: "O Merciful, have mercy on the fallen."
When Adam beheld the Angel turning him back, and closing the gate of the divine garden, he groaned greatly, and said: "O Merciful, have mercy on the fallen."
O Paradise, bear pain together with your master, who has been impoverished of you, and through the sound of your leaves, entreat the Fashioner to not close you. "O Merciful, have mercy on the fallen."
O Paradise full of virtue, all-holy, all-joyous, which was planted for Adam and was shut from Eve, entreat God for the fallen. "O Merciful, have mercy on the fallen."
-Excerpt from the Kontakion of St. Romanos: "On Adam's Lament", read on Forgiveness Sunday (source)
For the remainder of this beautiful Kontakion of St. Romanos, see here.