en_tn_lite_do_not_use/num/33/04.md

their firstborn

This refers to the firstborn sons. Alternate translation: "their firstborn sons" (See: rc://en/ta/man/translate/figs-explicit)

he also inflicted punishment on their gods

Yahweh proving that he is more powerful than all of the false gods that the Egyptians worshiped is spoken of as if Yahweh punished those false gods. Alternate translation: "he also proved that he is greater than their gods" (See: rc://en/ta/man/translate/figs-metaphor)