Let us do what the Prophet says:
I said, ‘I shall guard my ways
so that I may not offend with my tongue.
I have set a guard over my mouth.
I said nothing and humbled myself,
and I kept silence from good things.’ (Ps 39:2–3)
2 Here the Prophet shows that if at times we ought to be quiet for the sake of quiet itself, even from speaking good, how much more should we hold back from evil words on account of the punishment of sin. 3 Therefore, even though the words are good and holy and instructive, let permission to speak be given rarely even to the perfect disciples because of the importance of quiet, 4 for it is written:
In the midst of much talk,
you will not escape from sin, (Prov 10:19)
5 and elsewhere:
Death and life are in the hands of the tongue. (Prov 18:21)
6 For it is the teacher’s place to speak and teach; to be quiet and to listen belong to the disciple.
7 Therefore, if you must ask the superior for anything, ask with all humility and with the submission of reverence.
8 However, we condemn and bar forever and in every place offensive humor and idle talk and the stirring up of laughter, and we do not permit a disciple to open his mouth for such talk.