And so on their way they punished and put to a public and shameful death any whom they met of their fellow-countrymen who had become defiled: On their way means “As they went through Alexandria” (Contemporary English Version), that is, from the palace to the river. It may be inferred that they made some effort along the way to find the renegade Jews, but the narrative does not really say this. Obviously the public and shameful death is the punishment (they punished). The Jews returning up the Nile River to their homes found the Jews who had become defiled, that is, who had become unacceptable to God by abandoning his Law under threat of persecution, and killed them in public.

Here is an alternative model for this verse:

• As they left the city, whenever they met Jews who had violated the Jewish law, they killed them in public [or, where everyone could see them] so that they would be disgraced [or, shamed].

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.