Allah revealed to us what happened at their meeting with their father: Judah said: "Return to your father and say: '0 our father! Verily, your son (Benjamin) has stolen, and we testify not except according to what we know, and we could not know the unseen! And ask (the people of) the town where we have been, and the caravan in which we returned and indeed we are telling the truth.
He (Jacob) said: "Nay, but your ownselves have beguiled you into something. So patience is most fitting (for me). May be Allah will bring them (back) all to me. Truly He! Only He is All-Knowing, All-Wise."
And he turned away from them and said: "Alas, my grief for Joseph!" And he lost his sight because of the sorrow that he was suppressing. Surah 12: 81-84