Ante-Nicene Fathers/Volume III/Ethical/On Baptism/XVI
Chapter XVI.—Of the Second Baptism—With Blood.
We have indeed, likewise, a second font,[1] (itself withal one with the former,) of blood, to wit; concerning which the Lord said, “I have to be baptized with a baptism,”[2] when He had been baptized already. For He had come “by means of water and blood,”[3] just as John has written; that He might be baptized by the water, glorified by the blood; to make us, in like manner, called by water, chosen[4] by blood. These two baptisms He sent out from the wound in His pierced side,[5] in order that they who believed in His blood might be bathed with the water; they who had been bathed in the water might likewise drink the blood.[6] This is the baptism which both stands in lieu of the fontal bathing[7] when that has not been received, and restores it when lost.