From a spark of fire come many burning coals: This simply means that a single spark can light a big fire [many burning coals]. So we may translate “A single spark can start [or, light] a big fire.”

And a sinner lies in wait to shed blood: Lies in wait translates the same Greek verb as in verse 31. The sinner is looking for a chance—a chance to act against you, to do you harm, even to the point of violence. This chance is the spark that will light a big fire, which may bring about your downfall (verse 30). For blood see the comments on 8.16. An alternative model for this line is “in the same way a sinner is waiting for a chance to harm you” or even “in the same way a sinner’s evil plan can end in your murder.”

Verses 31-32 could be combined as follows:

• He will wait for a chance to bring about your death; meanwhile he will wait for a chance to make your good deeds appear evil, and find fault with your noblest actions. It only takes a single spark to light a roaring fire.

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.