Genesis 32:25

And when he saw, &c.— The Angel or Divine Person prevailed not, because he was willing to give Jacob the apparent superiority. But, at the same time, to convince him how easily he could have prevailed; had he thought fit, by a single touch he dislocated the joint of his thigh: and hinting that it was time for him to depart, in order to give Jacob an opportunity to pursue his journey, as the day was breaking, Jacob shews that he had fully learned who he was, by saying, I will not let thee go, unless thou bless me: and as blessing was the peculiar prerogative of God, he proves hereby sufficiently that he believed that Person to be Divine. See Grotius on the place.