Canon 64 A layman may not teach in public

That a layman ought not to raise a discourse or teach in public, thereby securing for himself the dignity of a teacher, but to yield to the order handed down by the Lord, and to open the ear to those who have received the grace of the word of teaching, and to be taught divine things by them. For in the one Church God has made different members, according to the voice of the Apostle; and Gregory the Theologian, interpreting this saying, plainly sets forth the order in these things, saying: This order let us reverence, brethren, this let us keep. Let one be an ear, another a tongue, another a hand, another something else; let one teach, another learn. And shortly after: And he who learns, in docility; and he who provides, in cheerfulness; and he who serves, in readiness; let us not all be a tongue, the readiest thing; not all apostles; not all prophets; let us not all interpret. And after some words: Why do you make yourself a shepherd, being a sheep? Why do you become the head, being a foot? Why do you attempt to be a general, being ranked among the soldiers? And elsewhere: Wisdom commands: Do not be quick in words; do not stretch yourself out beside the rich, being poor; nor seek to be wiser than the wise. And if anyone be caught infringing the present canon, let him be excommunicated for forty days.