Sirach 23:11-13

New Revised Standard Version Catholic Edition

¹¹ The one who swears many oaths is full of iniquity,
    and the scourge will not leave his house.
If he swears in error, his sin remains on him,
    and if he disregards it, he sins doubly;
if he swears a false oath, he will not be justified,
    for his house will be filled with calamities.

¹² There is a manner of speaking comparable to death;^[a]
    may it never be found in the inheritance of Jacob!
Such conduct will be far from the godly,
    and they will not wallow in sins.
¹³ Do not accustom your mouth to coarse, foul language,
    for it involves sinful speech.