So now sing praise with all your heart and voice: Ben Sira means that we should praise the Lord both with our mind (heart) and our voice, but it is obvious that we do not literally sing with the heart. The meaning of with all your heart and voice is “enthusiastically.” This line may be rendered “Now then, sing praises to the Lord, enthusiastically.”

And bless the name of the Lord: This seems to repeat what is in the first line. Perhaps a translator may say “and give him thanks” (Contemporary English Version).

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.