In this week's Torah reading we find Yehuda giving a long speech in front of Yosef about the suffering of YAakov in the case that Binyamin stays in Egipt. Yosef, moved by his brother, finally shows himself to his brothers and askes if his father is still alive. What's the point of the question? Furthermore, we don't find an answer to it...
Based on Likutei Sichot vol. 15, p. 387.