In the presence of a stranger do nothing that is to be kept secret: This does not necessarily mean that you and the stranger are alone. You should not do something private when a stranger is present, regardless of the presence of others. Something to be kept secret does not refer to anything shameful or sinful; ben Sira would not suggest that be done at all. But some things are legitimately “private” (New English Bible), not for general knowledge. You should not conduct business of this sort in the presence of someone whom you do not know. Alternative models may be “When strangers are around [or, near you], don’t do anything that you want kept secret” and “… anything that you don’t want others to know about.”

For you do not know what he will divulge; that is, the stranger may go out and tell what happened. The Greek of this line can be interpreted in another way, and the Handbook thinks Good News Translation is correct in going that way: “There is no way of knowing what will happen if you do.” The Greek verb translated he will divulge can be rendered “it will bring forth” (so Revised Standard Version footnote).

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.