For when they heard that through their own punishments the righteous had received benefit, they perceived it was the Lord’s doing: The Egyptians realized that Israel’s God had been acting against them, when they heard that their own suffering benefitted the Israelites. The connector For is better rendered as “and”; for example, “and when they learned….” In some languages it will be helpful to change the third person reference to the Lord in it was the Lord’s doing to second person: “it was your work, Lord” (Good News Translation).

A possible translation combining verses 12 and 13 is:

• They [or, Those ungodly people] groaned when they remembered what had happened. Not only did they remember their own punishment [or, the punishment they had received], but when they heard that the righteous had benefitted from it, their suffering was twice as painful. They realized that the Lord had done all this.

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.