Tertullian, On Baptism 7
Afterward, we step from the bath and are anointed with blessed oil, following the ancient rite by which priests were anointed with oil from a horn. This goes back to Aaron, whom Moses anointed. From that practice comes the very name ‘Christ,’ from ‘chrism’ meaning anointing—a title that fitted the Lord because He was made spiritual, anointed with the Spirit by God the Father, just as Acts says: ‘They were gathered together in this city against Your holy Son, whom You anointed’ (Acts 4:27). In the same way, the anointing runs on our bodies but works in our spirits, just as Baptism itself is a bodily act—we are plunged in water—whose spiritual effect is that we are freed from sins.
Latin
Exinde, egressi de lavacro, perungimur benedicta unctione de pristina disciplina, qua ungi oleo de cornu in sacerdotium solebant. Ex quo Aaron a Moyse unctus est: unde Christus dicitur, a chrismate quod est unctio, quae Domino nomen accommodavit, facta spiritualis, quia spiritu unctus est a Deo Patre, sicut in Actis: Collecti sunt enim vere in ista civitate adversus sanctum Filium tuum, quem unxisti. Sic et in nobis carnaliter currit unctio, sed spiritaliter proficit: quomodo et ipsius Baptismi carnalis actus, quod in aqua mergimur; spiritalis effectus, quod delictis liberamur.