So no one will pity a man who associates with a sinner: To avoid making this refer only to a man, Good News Translation restructures this line in the second person. To “run around with sinners” is an English idiom meaning to associate with or to be friendly with sinners, to keep company with them. So we may translate “In the same way nobody will feel sorry for you if you are friendly with [or, keep company with] sinners.”

And becomes involved in his sins: If you become a close companion of a sinner, it will not be long before you are involved in the same sinful activities (Contemporary English Version “start sinning yourself”). Friends like these are as dangerous as the snakes or wild animals that some people keep. If you get hurt from being around them, you cannot expect people to feel sorry for you.

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.