This looks like a lie; for Jacob either did not know this fact, or rather, was so well assured of Joseph's clemency and goodness, that he never feared his revenge. But guilt doth so awaken fear, that it makes a man never to think himself secure.
Related Commentaries of Genesis 50:16
Genesis 50:16
16 And they sent a messenger unto Joseph, saying, Thy father did command before he died, saying,