This is by Gregory of Nyssa. I found it at CCEL
You truly, O Lord, are the pure and eternal fount of goodness; … who did curse, and did bless; you did banish us from Paradise, and did recall us; you did strip off the fig-tree leaves … and put upon us a costly garment; you did open the prison and did release the condemned; you did sprinkle us with clean water, and cleanse us from our filthiness. No longer shall … the flaming sword encircle Paradise around, and make the entrance inaccessible to those that draw near; but all is turned to joy for us that were the heirs of sin; Paradise, yea, heaven itself may be trodden by man, and the creation, in the world and above the world, that once was at variance with itself, is knit together in friendship: and we … are made to join in the angels’ song, offering the worship of their praise.
– from “On the Baptism of Christ“