St. Theognostos ca. 14th cent.?
If you have been found worthy of divine and venerable priesthood, you have committed yourself sacrificially to die to the passions and to sensual pleasure. Only then dare you approach the awesome, living sacrifice; otherwise you will be consumed by the divine fire like dry tinder. If the seraphim did not dare to touch the divine coal without tongs (cf. Isa. 6:6), how can you do so unless you have attained dispassion? You must through dispassion have a consecrated tongue, purified lips, and a chaste soul and body; and your very hands, as ministers of the fiery, supraessential sacrifice, must be more burnished than any gold.
When your tears have washed you whiter than snow and your conscience is spotless in its purity, and when the angel-like white-ness of your outer garments reveals your soul’s inner beauty – then, and only then, you may in holiness touch holy things. Make sure that you do not rely only on human traditions-in celebrating the divine mysteries, but let God’s grace inwardly and invisibly fill you with the knowledge of higher things. (On the Practice of the Virtues, Contemplation and Priesthood 13, 18)