Esav hated Ya`akov because of the blessing with which his father blessed him. Esav said in his heart, *The days of mourning for my father are at hand. Then I will kill my brother Ya`akov.*
Thus says the LORD: *For three transgressions of Edom, yes, for four, I will not turn away its punishment; because he pursued his brother with the sword, and cast off all pity, and his anger raged continually, and he kept his wrath forever;
then Yisra'el sent messengers to the king of Edom, saying, Please let me pass through your land; but the king of Edom didn't listen. In the same way, he sent to the king of Mo'av; but he would not: and Yisra'el abode in Kadesh.
But Sichon didn't trust Yisra'el to pass through his border; but Sichon gathered all his people together, and encamped in Yahatz, and fought against Yisra'el.