Tell him the story of Majnun, or narrate the sorrow hidden behind the curtain.

Mir Taqi Mir is masterfully contrasting two types of sorrow. On the surface, you can tell the grand, famous story of Majnun—a tragic, dramatic tale. But the poet suggests that this isn't enough. True, profound sorrow, the kind that pierces the heart, is not the one that is visible or celebrated. It is the private, silent grief, the pain that exists 'behind the curtain'—the sorrow that only the soul truly knows.