This prayer is unique to the Maronite Catholic liturgy, said by the Priest after the Dismissal:
Remain in peace, O altar of God,
and I hope to return to you in peace.
May the sacrifice which I have offered upon you forgive my sins,
help me to avoid my faults,
and prepare me to stand blameless before the throne of Christ.
I know not whether I will be able to return to you again to offer sacrifice.
Guard me, O Lord,
and protect Thy Holy Church
so that She may remain the Way of Salvation and the Light of the World.
Congratulations on becoming a Maronite.