Now Judah comes to the nub of his argument. He has offered himself to his father as a guarantee that the young man will go back. If he goes back without Benjamin he will carry his own burden of guilt for ever, and be for ever guilty before his father. This he cannot bear. So he pleads that the Man will let him take Benjamin's punishment. But he is not just thinking of himself. He is also thinking of the effect on his father. He cannot bear to think of what it will do to his father.
Joseph sees here a different man from the one who callously sold him into slavery. And that, together with the thought of his father's sufferings and the love he has for his family, determines him to bring the whole affair to an end.