Before the universe was created, it was known to him; so it was also after it was finished may be rendered “Before he created the universe, he knew everything [there was to know] about it, and he still does.” Contemporary English Version provides a helpful model here:

• He knew all things
before he created them,
just as he knows them now.

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.