Moses now feared to wage war against Og, not only on account of his giant strength and huge size, which Moses had now witnessed with his own eyes, but he also thought: "I am only one hundred and twenty years old, whereas he is more than five hundred. Surely he could never have attained so great an age, had he not performed meritorious deeds." Moses also remembered that Og was the only giant that had escaped the hand of Amraphel, and he perceived in this a token of God's special favor toward Og.
Moses feared, moreover, that Israel in the recent war against Sihon might have committed sins, so that God would not now stand by them. "The pious are always afraid of the consequences of sin, and therefore do not rely upon the assurances God had made to them;" hence Moses now feared to advance upon Og even though God had promised him aid against his enemies. God, however, said to him: "What is thy hand, his destruction has been decreed since the moment when he looked with evil eyes upon Jacob and his family when they arrived in Egypt."
For even then God had said to him: "O thou wicked knave, why dost thou look upon them with all evil eye? Verily, thine eye shall burst, for thou shalt fall into their hands."