Deuteronomy 2:33

And the Lord our God delivered him before us
With their lands:

and we smote him and his sons, and all his people;
with the edge of the sword; slew them all: the Cetib or textual reading is "his son", though the Keri or margin is "his sons", which we follow. So Jarchi observes, it is written "his son", because he had a son mighty as himself, he says.