John Gill Commentary Genesis 46:19

"The sons of Rachel Jacob`s wife: Joseph and Benjamin." — Genesis 46:19 (ASV)

The sons Rachel, Jacob's wife
The wife of his affection and choice, his principal wife, yea, his only lawful wife; Zilpah and Bilhah were his concubines, and as for Leah, she was imposed and forced upon him: Joseph and Benjamin ;
the first was in Egypt already, the other now went down with Jacob.