Guru Har Rai Ji.

Dara Shikoh the elder son of the emperor Shahjahan fell ill, in spite the best efforts of the Hakims (herbalists) he would not get better. Information reached the Royal Hakim that Guru Har Rai who sits in the house of Guru Nanak has a rare gift to cure people. The prince came to Guru Ji in person. Guru Ji administered a rare herbal medicine, the prince made a rapid recovery.