I am black but beautiful, daughters of Jerusalem, as the tents of Kedar, as the curtains of Solomon.
In this verse, Rashi says, the nation of Israel answers the other nations. They have complained that Israel has been blackened by her sins and Israel replies that even though we may have been blackened by our own deeds, we remain beautiful thanks to the deeds of our ancestors. Even more, we still have beautiful deeds of our own! For example, if we stumbled in the matter of the golden calf, that is counterbalanced by our merit for accepting the Torah. (Rashi goes on to explain that the other nations are referred to here as “daughters of Jerusalem” because Jerusalem is destined to grow into a metropolis. Rashi gives several examples of satellite cities being referred to as “daughters” – for example, Joshua 15:45.)