Moses
Genesis 26:35ESV·traditional attribution

and they made life bitter for Isaac and Rebekah.

Matthew Henry Presbyterian @wholebiblehenry

Here is, 1. Esau's foolish marriage - foolish, some think, in marrying two wives together, for which perhaps he is called a fornicator (Heb 12:16), or rather in marrying Canaanites, who were strangers to the blessing to Abraham, and subject to the curse of Noah, for which he is called profane; for hereby he intimated that he neither desired the blessing nor dreaded the curse of God. 2.

Commenting on Genesis 26:34-35

Adam Clarke Methodist @methodicalclarke

Which were a grief of mind - Not the marriage, though that was improper, but the persons; they, by their perverse and evil ways, brought bitterness into the hearts of Isaac and Rebekah. The Targum of Jonathan ben Uzziel, and that of Jerusalem, say they were addicted to idol worship, and rebelled against and would not hearken to the instructions either of Isaac or Rebekah.

Keil & Delitzsch Lutheran @keilanddelitzsch

Gen 26:34-35 Esau’s Marriage. - To the various troubles which the Philistines prepared for Isaac, but which, through the blessing of God, only contributed to the increase of his wealth and importance, a domestic cross was added, which caused him great and lasting sorrow.

Commenting on Genesis 26:34-35