And told him, saying, Joseph is yet alive, and he is governor over all the land of Egypt. And Jacob's heart fainted, for he believed them not. Jacob's heart fainted - Probably the good news so overpowered him as to cast him into a swoon. He believed them not - he thought it was too good news to be true; and though it occasioned his swooning, yet on his recovery he could not fully credit it. See a similar case, Luke 24:41 (note).
Related Commentaries of Genesis 45:26
Genesis 45:26
26 And told him, saying, Joseph is yet alive, and he is governor over all the land of Egypt. And Jacob's heart fainted, for he believed them not.