Ambrose of Milan

For this is the price of our liberty, as Peter says, ye were redeemed with the precious Blood, not indeed of a lamb, but of Him Who came as a lamb, in meekness and humility, and redeemed the whole world with the one offering of His Body, as He himself says, I was brought as a lamb to the slaughter. Wherefore John also says, Behold the Lamb of God, which taketh away the sin of the world.