(Ibid. 16) "But from the cities of these people (the seven nations) … you shall not allow any soul to live": (But you shall slay them) by the sword.
(Ibid. 17) "But you shall utterly destroy them": I might think that their spoil were forbidden to you; it is, therefore, written (Ibid. 6:11) "and houses full of all good." "the Chitti, the Emori, the Canaani, etc."
"as the L-rd your G-d commanded you": to include the Girgashi.
(Devarim 20:18) "So that they not teach you to do according to all their abominations": whereby we are taught if they repented, they are not killed.