Genesis 26:35

And they were a grief of mind to Isaac and to Rebecca.

Genesis 6:2

that the sons of God saw the daughters of men that they were fair, and took themselves wives of all that they chose.

Genesis 27:46-2

And Rebecca said to Isaac, I am weary of my life because of the daughters of Heth. If Jacob take a wife of the daughters of Heth, such as these, of the daughters of the land, what good should my life do me?

Genesis 28:8

And Esau saw that the daughters of Canaan were evil in the sight of 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 the daughters of men that they were fair, and took themselves wives of all that they chose.
Genesis 27:46
And Rebecca said to Isaac, I am weary of my life because of the daughters of Heth. If Jacob take a wife of the daughters of Heth, such as these, of the daughters of the land, what good should my life do me?
Genesis 28:1
And Isaac called Jacob, and blessed him, and charged him, and said to him, Thou shalt not take a wife of the daughters of Canaan.

General references

Genesis 34:9
And make marriages with us: give your daughters to us, and take our daughters to you.