Tertullian, ibid.  “Just as after the waters of the deluge, by which the old iniquity was purged—after the baptism, so to say, of the world—a dove was the herald which announced to the earth the assuagement of celestial wrath,.…so to our flesh, as it emerges from the font after its old sins, flies the dove of the Holy Spirit, bringing us the peace of God, sent out from heaven where the Church is, the typified ark.”  Compare also Hippolytus, The Holy Theophany, §§ 8, 9, a treatise with which Cyril has much in common.