This discourse was taught by the Rebbe in the week of Chanukah in 1969. It develops the theme that in a time of Exile opposites can join, and the darkness and light signified by the terms ‘sing’ and ‘rejoice’ (as explained by the Zohar) can coexist at the same time and place.  Turning to the Sedra Miketz it also explains how Joseph spiritually prepared the way for the Children of Israel to enter Egypt and survive there as Jews. As a Tzaddik, his being in Egypt and even more, his leadership role there, empowered the Jewish people.