Do not accustom your mouth to lewd vulgarity: Compare this line with the first line of verse 9, and compare Good News Translation‘s translation of both lines. An alternative model for this line is “Do not fall into the habit of using bad [or, vulgar] language.”

For it involves sinful speech: Good News Translation is brief and to the point here with “it is sinful.”

Quoted with permission from Bullard, Roger A. and Hatton, Howard A. A Handbook on Sirach. (UBS Helps for Translators). New York: UBS, 2008. For this and other handbooks for translators see here.