Below is the complete daily lesson as delivered by The Rav, Rabbi Eliezer Berland shlit"a, on Sunday night, the eve of the 16th of Teves, Parshas Shemos, after the Ma’ariv prayer:

So Serach bas Asher volunteered to die. Because whoever would tell Yaakov that Yosef is alive would “die on the spot.” Yaakov sat on the ground for twenty-two years, with terrible crying, refusing to be comforted. With sackcloth on his waist, he did not change his clothes, he did not bathe, he did not eat anything. Twenty-two years—aside from Yosef’s pain and Yaakov’s pain—something for which there is no forgiveness in the world. That is why there was Auschwitz, and things like it… the destruction of the First Beis HaMikdash, the Second Beis HaMikdash—everything is because of the sale of Yosef. Because the brothers did not ask forgiveness at all. Yosef asked forgiveness: “Forgive me for putting you in prison for three days; for separating Shimon…” The one who asked forgiveness was Yosef—the Tzaddik asks forgiveness. A person doesn’t even recognize his own sins! He doesn’t even know that he is sinning! He doesn’t grasp it. They didn’t grasp at all that he… They said the opposite: “He became a king; he came out distinguished.” Look—we were supposed to go down in iron chains, and we went down in golden carriages. How wondrous! How enjoyable! How beautiful… Therefore this sin is not— even when Moshiach comes, they must bring one goat as a sin-offering; even at Techiyas HaMeisim, a goat. And it is all to atone for [the sale of] Yosef—because this is something that is never forgiven. But in the merit of Serach bas Asher, then she sweetened everything. With her dancing and her song—“Yosef is still alive”—she sweetened everything. And in this merit we will merit the complete Geulah speedily in our days, Amen!‏

To watch the replay — the lesson is at 1:13:13