On Baptism by Tertullian
Chapter VIII.--Of the Imposition of Hands. Types of the Deluge and the Dove.
In the next place the hand is laid on us, invoking and inviting the Holy Spirit through benediction. Shall it be granted possible for human ingenuity to summon a spirit into water, and, by the application of hands from above, to animate their union into one body with another spirit of so clear sound; and shall it not be possible for God, in the case of His own organ, to produce, by means of |holy hands,| a sublime spiritual modulation? But this, as well as the former, is derived from the old sacramental rite in which Jacob blessed his grandsons, born of Joseph, Ephrem and Manasses; with his hands laid on them and interchanged, and indeed so transversely slanted one over the other, that, by delineating Christ, they even portended the future benediction into Christ. Then, over our cleansed and blessed bodies willingly descends from the Father that Holiest Spirit. Over the waters of baptism, recognising as it were His primeval seat, He reposes: (He who) glided down on the Lord |in the shape of a dove,| in order that the nature of the Holy Spirit might be declared by means of the creature (the emblem) of simplicity and innocence, because even in her bodily structure the dove is without literal gall. And accordingly He says, |Be ye simple as doves.| Even this is not without the supporting evidence of a preceding figure. For 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, when she had been sent her way out of the ark, and had returned with the olive-branch, a sign which even among the nations is the fore-token of peace; so by the self-same law of heavenly effect, to earth -- that is, 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 the heavens where is the Church, the typified ark. But the world returned unto sin; in which point baptism would ill be compared to the deluge. And so it is destined to fire; just as the man too is, who after baptism renews his sins: so that this also ought to be accepted as a sign for our admonition.