In prophecy things that will happen in the future are described as something in the past. This emphasizes that the prophecy will certainly come true. Alternate translation: "enemies from other countries will take my people, Israel, as slaves."
What they do not understand can be made explicit: "because they do not understand Yahweh or his law"
## their masses ##
"their common people"
## death has made its appetite greater and has opened its mouth very wide ##
This phrase compares death to an animal that is ready to eat other animals. It emphasizes that many, many people will die. Alternate translation: "Death is like a hungry animal that has opened its mouth wide to eat up many people." (See: [[rc://en/ta/man/translate/figs-metaphor]])