Appendix D — On the Sign of the Cross
In the second chapter of his fifth book Durandus enters at great length into this subject. The reason for making the sign is to drive away evil spirits, who, as S. Chrysostome says, ‘always flee when they see the sign of the cross, as fearing that staff by which they have been wounded.’ The pole on which the brazen serpent was raised, the crossing of Jacob’s hands when blessing Joseph’s children, the mark tau (Ezekiel ix, 4) on the forehead, and the seal on the forehead in the Apocalypse, are some of the representations of the cross here alleged. The cross is to be made with three fingers, that is, the thumb and two fingers, in honour of the Trinity. The Jacobites and Eutychians use only one finger. Next the different methods of crossing are discussed. The sign ought to be made at the end of the gospel, the creeds, the Lord’s Prayer, the Gloria in excelsis, the Sanctus, the Agnus Dei, the Benedictus, Magnificat, Nunc dimittis, at the beginning of the hours, the end of the Mass, when the priest gives the benediction, and whenever mention is made of the Cross of the Crucified. See also our author in his sixth book De die Parasceu.