Rashi on Deuteronomy 3:11/רש"י על דברים ג׳:י״א

1מיתר הרפאים [ONLY OG … REMAINED] OF THE REST OF THE REPHAIM whom Amraphel and his allies slew in Ashteroth-Karnaim (Genesis 14:5), and he (Og) escaped from the battle, as it is said, (Genesis 14:13) "And the fugitive came", and that was Og (Genesis Rabbah 42:8; cf. Rashi on Genesis 14.13.1).

2באמת איש AFTER THE CUBIT OF A MAN — i.e. after the cubit of Og.