פירוש על דברים 3:2

אל תירא אתו DO NOT FEAR HIM — In the case of Sihon, however, it did not feel it necessary to state, “Do not fear him״!? But in the case of Og Moses feared lest the merit that he (Og) had been of service to Abraham might avail him, as it is said, (Genesis 14:13: see Rashi thereon), "And the fugitive came", and that was Og (Genesis Rabbah 42:8; see Rashi on Numbers 21:34).