“My lord asked his servants, saying, ‘Have you a father or a brother?' And we said to my lord, ‘We have a father, an old man, and a child of his old age, a younger one,' and his brother is dead, and he is all that is left of his mother, and his father loves him.”
Judah is now determined that the Man will realise the full position, for he knows it is the only hope. Perhaps there is something in this Man who has been such an enigma, that will move him to mercy. First then he establishes the position of the young man in his father's affections.
“A child of his old age.” One on whom in his old age he depended for personal care and support, and the only son of his mother. Of course the Man will not realise how important Rachel had been to Jacob, but Judah does.