It is not possible to diminish or increase them: The idea here is that no one can think of a merciful deed that the Lord has not done or destroy the force of one that he has done. Good News Translation‘s two separate clauses, both in the first person plural, are effective. Contemporary English Version is also helpful with “Nor can we make that number larger or smaller.” Another possible approach is “We cannot possibly make them less merciful or more in number.”

Nor is it possible to trace the wonders of the Lord: The Greek verb translated trace here is the same one rendered “search out” in verse 4. It is best to see this line not as repetitious, but as a summary statement of verses 1-6a. The translator can point the reader in the right direction by translating this line as a separate sentence, as Good News Translation does. In some languages it will be helpful to begin the statement with “To sum up” or “In conclusion”; for example, “In conclusion, it is not possible to understand the marvelous things the Lord has done.”

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.