Bereshis 28:13-14

And, hinei, HASHEM stood above it, and said, I am HASHEM Elohei Avraham thy av, and Elohei Yitzchak; ha'aretz whereon thou liest, to thee will I give it, and to thy zera; And thy zera shall be as the dust of ha'aretz, and thou shalt spread abroad to the west, and to the east, and to the north, and to the south; and in thee and in thy zera shall kol hamishpochot haadamah be blessed.