When they see him, they will be shaken with dreadful fear, and they will be amazed at his unexpected salvation: The ungodly did not expect the righteous to be saved (2.17), so when they see them standing there, they become afraid, knowing the punishment that must be in store for themselves. Good News Translation does well to reverse the lines. An alternative model that clarifies the subject is:

• The ungodly will be amazed to see them safe [or, unharmed], and will tremble with terrible fear.

Quoted with permission from Bullard, Roger A. and Hatton, Howard A. A Handbook on The Wisdom of Solomon. (UBS Helps for Translators). New York: UBS, 2004. For this and other handbooks for translators see here.