The Daily Shiur of our Rebbe Rav Eliezer Berland shlit”a, from Sunday night, 4 Elul, parashat Ki Tetzei, after Maariv:
“So whoever would reveal to Yaakov Avinu that Yosef is alive would die on the spot. For twenty-two years, they deceived Aba, Saba, the greatest Tzaddik of all generations. Serach bat Asher did not fear. She said, ‘I am ready to die; the main thing is to make my grandfather happy.’ And she began to sing, ‘Yosef is still alive, and king in Egypt, and has two sons, Menashe and Ephraim.'”