Have you sinned, my son?: The phrase my son is a phrase used by a teacher to a student; it is warm and respectful but does not indicate that the writer is the reader’s actual father. See the comments on 2.1.

Do so no more, but pray about your former sins: To pray about sins means to ask the Lord to forgive them.

Contemporary English Version has a helpful model for this verse:

• Students, if you
are sinning, stop.
Ask God to forgive 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.