They answered Joshua, and said, Because it was certainly told your servants, how that Yahweh your God commanded his servant Moses to give you all the land, and to destroy all the inhabitants of the land from before you; therefore we were sore afraid for our lives because of you, and have done this thing.
and to destroy all the inhabitants of the land from before you; as the gift of the land of Canaan to Israel was often spoken of by the Lord to Moses, and frequently mentioned by him; so there were instructions given him from the Lord, and which lie delivered to Israel, utterly to destroy the inhabitants of Canaan, so, that these people had accurate intelligence and information of this matter; see Deuteronomy 7:1: