 The Midrash taught that Moses was afraid, as he thought that perhaps the Israelites had committed a trespass in the war against Sihon, or had soiled themselves by the commission of some transgression.God reassured Moses that he need not fear, for the Israelites had shown themselves perfectly righteous.The Midrash taught that there was not a mighty man in the world more difficult to overcome than Og, as says, "only Og king of Bashan remained of the remnant of the Rephaim."