True origin of baptismal exorcism: adult rite, catechesis, and energumen expulsion
Its true origin is threefold.
First: the old rite around adults about to be baptized. For a time baptism was preceded by putting off clothes or shoes, solemn renunciation, turning east, anointing the whole body, and a human breath with divine power driving the demon out — a human breath with divine power driving the demon out — as Cyprian first notes at the saving water of baptism (Epistle 76 to Magnus). The baptized person himself also blew out or spat as if casting the demon — that is, wicked affections — from his own breast.
Second: the old catechetical rite, in which catechumens were breathed upon to drive off the demon of ignorance and malice (Balsamon and others on Laodicea canon 26). So exorcists and catechists were the same office, as we show more fully in the Church History — and catechizing passed over into the baptismal rite.
Third: the exorcism of energumens, the demon-possessed, which alone stood in the first and second ages outside baptism, and by force of the promise (Mark 16:17). Later every person outside Christ was treated as somehow demon-possessed.
Latin
VERA autem ejus origo est, 1. Ab antiquo ritu circa adultos baptizandos, pro tempore ut praevia fuit Baptismo exutio vestium, aut calceorum, praevia solemnis abrenunciatio, conversio ad Orientem, unctio totius Corporis, ita φύσημα, ἐμφύσησις, exsufflatio seu fugatio Daemonis, voce humanâ, virtute divinâ, ut primis hujus ritûs meminit Cyprianus, ad salutarem aquam Baptismi, Epist. LXXVI. ad Magnum. Ipso etiam baptizato exsufflante seu exspuente quasi Daemonem, id est, improbos affectus, ex pectore suo. 2. Ab antiquo ritu κατηχήσεων, quo Catechumeni exsufflabantur, fugato scilicet Daemone ignorantiae, malitiae, de quo ad Canonem Laod. XXVI. Balsamo, & alii. Unde ἐξορκισταὶ, ἐφορκισταὶ, iidem qui κατηχηταί, ut in Ecclesiae Hist. nos pluribus. Et ita Catechizationum ritus in Baptismalem abiit. 3. Ab exorcismo Energumenorum δαιμονιώντων, qui solus obtinuit primâ & secundâ Aetate, extrà usum Baptismi, & quidem vi promissionis, Marc. XVI.17. Supponendis deinceps Energumenis iis omnibus, seu à Daemone quodammodo possessis, quotquot extrà Christum essent.