Moussar sur La Genèse 32:30

Since the blessing Jacob received from his father had been of a material nature, such as "the dew of the heavens, the fat parts of the earth, etc." [seeing Isaac thought he was blessing Esau], he could not really receive Isaac's spiritual blessings until he had successfully confronted Esau, i.e. had experienced the fear of Esau approaching him with four hundred armed men. Jacob's very desire to belong to the choicest of the בני עליה, the spiritually most refined human beings, necessitated that he undergo a thorough process of refinement. His stay at Laban, i.e. physical and mental hardship for over twenty years were all part of the preparation for receiving the ultimate spiritual blessings. After Jacob had successfully confronted the spiritual power of Esau in his nocturnal encounter in Genesis 32,25 ויאבק איש עמו (compare Bereshit Rabbah 77,3), he finally obtained the consent of his adversary that he was entitled to the blessings he had received from his father. This is why Esau said in 33,9: "you may keep what is yours." Esau's spiritual counterpart had already acknowledged this during the struggle when he had bestowed a blessing on Jacob in 32,30: ויברך אותו שם, "He blessed him there." At that time Jacob was also informed about the forthcoming change of his name to ישראל. The Esau on earth, had previously called him Jacob as a slur when he had felt himself betrayed in 27,36.