The Torah in Parashat Vayishlach tells the mysterious story of Yaakov's nighttime wrestle with an assailant as he makes his way towards Canaan, where he would reunite with his brother Esav. By the end of the narrative it becomes clear that Yaakov's assailant is angelic, rather than human, as Yaakov demands from him a blessing and he renames Yaakov "Yisrael," a name-change that is confirmed by God later in the parasha (35:10).
