This was one of the Canticles in Morning Prayer for February 29th:
Canticle 14 A Song of Penitence
Kyrie Pantokrator Prayer of Manasseh 1-2, 4, 6-7, 11-15
O Lord and Ruler of the hosts of heaven, *
God of Abraham, Isaac, and Jacob,
and of all their righteous offspring:
You made the heavens and the earth, *
with all their vast array.
All things quake with fear at your presence; *
they tremble because of your power.
But your merciful promise is beyond all measure; *
it surpasses all that our minds can fathom.
O Lord, you are full of compassion, *
long-suffering, and abounding in mercy.
You hold back your hand; *
you do not punish as we deserve.
In your great goodness, Lord,
you have promised forgiveness to sinners,*
that they may repent of their sin and be saved.
And now, O Lord, I bend the knee of my heart, *
and make my appeal, sure of your gracious goodness.
I have sinned, O Lord, I have sinned, *
and I know my wickedness only too well.
Therefore I make this prayer to you: *
Forgive me, Lord, forgive me.
Do not let me perish in my sin, *
nor condemn me to the depths of the earth.
For you, O Lord, are the God of those who repent, *
and in me you will show forth your goodness.
Unworthy as I am, you will save me,
in accordance with your great mercy, *
and I will praise you without ceasing all the days of my life.
For all the powers of heaven sing your praises, *
and yours is the glory to ages of ages. Amen.