ויכר יוסף את אחיו והם לא הכירוהו
Horav Tzvi Hirsch Ferber, zl, explains this pasuk practically. Yosef always viewed his brothers through the lens of filial love – as brothers. Indeed, whenever the Torah mentions Yosef’s relationship toward his brothers, it always uses the word ach, brother: Es achai anochi mevakeish, “I am searching for my brothers” (Bereishis 37:16); Va’yehi kaasher ba Yosef el echav, “And it was when Yosef came to his brothers” (Ibid. 37:23); Va’yeilech Yosef achar echav, “And Yosef went after his brothers” (Ibid. 37:17). Yosef never once lost his relationship with his brothers, but – v’heim lo hikiruhu, “They (however) did not recognize…