Charles Ellicott Commentary Genesis 34:5

"Now Jacob heard that he had defiled Dinah his daughter; and his sons were with his cattle in the field: and Jacob held his peace until they came." — Genesis 34:5 (ASV)

Jacob heard. — As Dinah did not return home (Genesis 34:26), her father probably learned of her dishonour from the maidservants who had gone out with her. But “he held his peace,” chiefly from his usual cautiousness, as he was no match for the Hivites, but partly because Leah’s sons had the right to be the upholders of their sister’s honour.