Or HaChaim on Genesis 28:13/אור החיים על בראשית כ״ח:י״ג

1 והנה ה׳ נצב עליו. And here G'd was standing upon it. The word עליו also refers to Jacob, i.e. that he perceived G'd as standing above him. This is in line with what Bereshit Rabbah 82,6 tells us that the patriarchs were the carriers of G'd's presence. Inasmuch as Jacob was the fourth "leg" of that מרכבה [perceived here as a chair G'd is transported on, Ed.] G'd leaned more heavily on Jacob than on the other three "legs." The singular עליו is justified then.

2אלוקי אברהם אביך, "the G'd of your father Abraham." The reason the Torah added the superfluous word "your father," as well as the reason why Abraham is described as Jacob's father without the addition of Isaac was intended to emphasise that Esau had no share in the heritage of Abraham. The Torah here made Jacob the sole heir of Abraham. This heritage did not come to Jacob via his father Isaac but directly from his grandfather Abraham. I have already explained in chapter 16,21 that there was never a question of Ishmael sharing in Abraham's inheritance since Ishmael was legally a slave and as such could not inherit anything from anybody. Ishmael was pointedly described as "the son of this slavewoman" not as Abraham's son (21,13). Esau was precluded from claiming any part of Abraham's inheritance.

3While it is true that the fact that a son is a heretic does not disqualify him from inheriting his father's estate (Kidushin 18), in this instance the gifts and blessings bestowed upon Abraham by G'd were given him with the express understanding that they be handed down to Jacob afterwards as we know from Genesis 21,12 that his seed would be known only through Isaac (Nedarim 31). Although the expression זרע does not imply that such seed must be morally fit in order to qualify for that description and therefore for the right to inherit, the fact that all the blessings of Abraham were transferred to Jacob excludes Esau as an heir. It is true that in connection with people who offer their children to the idol Moloch we find in Sanhedrin 64 that the term זרעו is used by the Torah, and that it includes children who have not turned out properly. The fact remains that usually the word זרע refers to children who follow in the footsteps of their fathers. When the Talmud Kidushin 18 quotes Deut. 2,5 as proof that Esau did inherit, this is in connection with Esau's children receiving an inheritance from their father; it does not mean that Esau himself was qualified to inherit from his grandfather Abraham.