Genesis 26:35

and they were a source of grief to [Esau’s parents] Isaac and Rebekah.

Genesis 6:2

that the sons of God saw that the daughters of men were beautiful and desirable; and they took wives for themselves, whomever they chose and desired.

Genesis 27:46-2

Then Rebekah said to Isaac, “I am tired of living because of the daughters of Heth [these insolent wives of Esau]. If Jacob takes a wife from the daughters of Heth, like these daughters of the land, what good will my life be to me?”

Genesis 28:8

So Esau realized that [his two wives] the daughters of Canaan displeased Isaac his father;

Treasury of Scripture Knowledge

Summary

Which were a grief of mind unto Isaac and to Rebekah.

General references

Bible References

Which

Genesis 6:2
that the sons of God saw that the daughters of men were beautiful and desirable; and they took wives for themselves, whomever they chose and desired.
Genesis 27:46
Then Rebekah said to Isaac, “I am tired of living because of the daughters of Heth [these insolent wives of Esau]. If Jacob takes a wife from the daughters of Heth, like these daughters of the land, what good will my life be to me?”
Genesis 28:1
So Isaac called Jacob and blessed him and charged him, and said to him, “You shall not marry one of the women of Canaan.

General references

Genesis 34:9
And [beyond that] intermarry with us; give your daughters to us [as wives] and take our daughters for yourselves.