A rich man will exploit you if you can be of use to him may be rendered “If a rich person finds that you can be helpful to him, you can be sure that he will take advantage of you.” The Greek phrase rendered will exploit you is an awkward literal translation of the Hebrew, which means “will treat you like his slave.” On the basis of the Hebrew, we suggest the following model for this line: “If a rich person finds that you can be helpful to him, he will treat you like his slave.” A rich man is literally “He” in Greek (see the Revised Standard Version footnote). This pronoun obviously refers back to the rich man in the previous verse, so Revised Standard Version makes this explicit.
But if you are in need he will forsake you: Good News Translation provides a good model here with “but when you need him, he will leave you helpless.”
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.
