If a man washes after touching a dead body, and touches it again, what has he gained by his washing?: The reference here is to Num 19.11-12. A person became ritually unclean by touching a corpse, and became ritually clean by washing with special water. Contemporary English Version has a helpful model:

• If you are unclean
from touching a dead body,
what’s the point of washing
if you touch the body again?

This is a rhetorical question, so we suggest the following model for languages that cannot use rhetorical questions:

• If you are unclean from touching a dead body, it is foolish to wash your hands if you touch the body again.

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.