By doing this may be rendered “When he did this.”

And by endowing their sacred enclosures with gifts means Philopator offered gifts to their temples and other places of worship. Contemporary English Version renders this clause well with “and donate gifts to their places of worship.”

He strengthened the morale of his subjects means he made his subjects feel safer or have more confidence in him as their ruler. Subjects are citizens of a country ruled by a king.

An alternative model for this verse is:

• When he did this, he made gifts to their temples [or, places of worship]. This [or, These actions] gave the people more confidence in him as their ruler.

Quoted with permission from Bullard, Roger A. and Hatton, Howard A. A Handbook on 3-4 Maccabees. (UBS Helps for Translators). Miami: UBS, 2018. For this and other handbooks for translators see here.