This was a foolish statement, but Jacob did not vow before the LORD, so he did not have to make good on his promise.
Rachel is deceitful and lies, still depends on the idols.
Esau’s wives so far were Hittites. That explains why Rebekah in chapter 27:46 “I’m disgusted with living because of these Hittite women. If Jacob takes a wife from among the women of this land, from Hittite women like these, my life will not be worth living.” It was not prejudice, it was the friction between mother-in-law and daughters-in-law.
Jesus repeats this phrase when he first met Nathaniel
And who has ever sung this Sunday School song?
Rebekah: Let the curse fall on me. She didn’t have it easy after that.
Rebekah was the original inventor of the plot for Isaac to give Jacob the blessing rather than Esau after Jacob had extorted Esau’s birthright. By deceit they fulfilled God’s will. The Bible shows how sinful man can still fulfill God’s purpose.
After Sarah’s death Abraham married one of his concubines. Keturah already had six sons with Abraham, according to first Chronicles 1:32-34

Ishmael was there at Abraham’s death, and helped bury Abraham. Thus he had not moved far away yet.
Of particular interest is Ishmael’s second son, Kedar. His name is closely associated with Arabia. But Kedar lived much closer to Jerusalem than what the Muslims suggest. They claim he moved to what is now Mecca, but according to Isaiah 60:7 he must have lived much closer.
All Kedar’s flocks will be gathered to you,
the rams of Nebaioth will serve you;
they will be accepted as offerings on my altar,
and I will adorn my glorious temple.
The lambs and other animals used for sacrifices were raised much nearer Jerusalem so they could more easily be driven as herds.
And this is the reason God said: Esau have I hated. Esau did not consider the spiritual dimension of his birthright.