When visiting Chicago, Swami Vivekananda stayed in the house of a businessman who was an associate of John D. Rockefeller. Many times had Mr. Rockefeller heard his friends talking about an extraordinary and wonderful Hindu monk, and many times he had been invited to meet Swamiji but always refused.
At that time Rockefeller was not yet at the peak of his fortune, but was already powerful and strong-willed, a hard man to advise. One day, on a whim, the millionaire briskly walked through the door and said he wanted to see the Hindu monk. Swami Vivekananda, who was behind his writing table, did not even lift his eyes when the magnate entered the study room. In their ensuing conversation, Swami told Rockefeller secrets about his past that Rockefeller alone knew. Then, Swami boldy explained that God had given him all his wealth in order that he might have an opportunity to help people and do good.
Annoyed that someone dared to tell him what to do, Rockefeller stormed out. Coming back a week later, he brought plans to donate an enormous sum of money to charity. This was Rockefeller’s first large donation to the public welfare. “Well, there you are,” he said to Vivekananda, “You can thank me for it.” Swamiji then said softly, “No sir, it is for you to thank me.”
source: The Complete Works of Swami Vivekananda, vol. 9