On their gods — Their false gods, namely those beasts which the brutish Egyptians worshipped as gods, which were killed with the rest, for the first — born both of men and beasts were then killed. Probably their images likewise were thrown down, as Dagon afterward before the ark.
Related Commentaries of Numbers 33:4
Numbers 33:4
4 For the Egyptians buried all their firstborn, which the LORD had smitten among them: upon their gods also the LORD executed judgments.