In the relics of the saints the Lord Christ has provided us with saving fountains which in many ways pour out benefactions and gush with fragrant ointment. And let no one disbelieve. For, if by the will of God water poured out of the precipitous living rock in the desert, and for the thirsty Sampson from the jawbone of an ass, is it unbelievable that fragrant ointment should flow from the relics of the martyrs? Certainly not, at least for such as know the power of God and the honor which the saints have from Him.
In Saint John of Damascus: Writings (The Fathers Of The Church A New Translation Vol. 37), 1958, 1999, Frederic H. Chase, Trans., Catholic University of America Press, ISBN 0813209684 ISBN 9780813209685 p. 368.