Self-incrimination[1]
ויגדו לו לאמר עוד יוסף חי וכי-הוא משל בכל-ארץ מצרים ויפג לבו כי לא-האמין להם: וידברו אליו את כל-דברי יוסף אשר דבר אלהם וגו’
[The brothers] said to [Yaakov]: “Yosef is still alive! He is the ruler over the entire land of Egypt!” [Yaakov] was skeptical, as he didn’t believe them. They told him everything Yosef had told them.[2]
Yosef had been missing for twenty-two years. He was presumed dead, but it was never confirmed. His father Yaakov had given up on ever seeing him again. Now, Yosef had become the viceroy in Egypt. After revealing his identity to his estranged brothers, he arranged for them to bring their father Yaakov and their entire family to move to Egypt. When the brothers told Yaakov what had happened, and that Yosef was alive, he initially wouldn’t believe them. Why not?
How did Yosef get separated from his family? His brothers sold him into slavery. This is something that Yaakov never knew about[3]. They pretended that a wild animal had killed him, since they found his special coat covered in blood. Now, what were the brothers trying to convince Yaakov? That Yosef was still alive and in Egypt. How did he get there? He must have been sold as a slave, as was common in those days. If so, how did the brothers get ahold of his coat? Why was it covered in blood? The logical conclusion is that if Yosef is alive, his brothers sold him into slavery. It was this that he refused to believe, until they managed to finally convince him.
We can develop this idea a little deeper. The verse says that the brothers told Yaakov everything that Yosef had told them. Perhaps this included the words of comfort which Yosef shared to his brothers[4]. When he finally revealed his identity, he told his brothers not to worry about selling him as a slave. It was an act of Hashem, behind the scenes. Yosef had to be sent to Egypt to allow him the opportunity to become the viceroy of Egypt, giving him the power to save his family during the great famine. The brothers told this to Yaakov to emphasize that they couldn’t be held responsible for selling Yosef. Hashem so-to-speak compelled them, in order to fulfill His divine plan. This could explain why Yaakov eventually believed them. Although they had done a terrible thing by selling Yosef, it wasn’t their fault.
Good Shabbos
[1] Based on Chasam Sofer Al HaTorah to Genesis 45:26
[2] Genesis loc. cit., v. 27
[3] Ramban ad. loc.
[4] Rabbeinu Bachaye ad. loc., quoting the Ramban loc. cit., says that the brothers didn’t incriminate themselves. They didn’t mention anything about selling Yosef. I would add that this could be what motivated Rashi to say that they shared a secret code from Yosef to their father. This is what ultimately got Yaakov to be convinced that Yosef is alive