That is, in the present context, the people of Israel have no right to enslave the Judahites, since it was not they, but God himself, who defeated them in battle! The prepositional phrase ‘to yourselves’ (lākem) has an emphatic position which is ignored by the translation. It is not you who smote them, you have no right to subjugate them! In order not to aggravate their own guilt, the Israelites should now let the captives free.
