Mathur’s doubts still remained. With the idea of testing him further, he one day said to the Master: “Even God has to obey His own laws. Once a law is set up by God, not even He can overrule it.” Sri Ramakrishna replied: “What do you mean? He who makes a law can unmake it if He so desires, or He can replace it with another law.” But Mathur refused to accept this opinion, saying: “It is God who made the law that a red flower tree will produce only red flowers and never white ones. Let me see if He can produce a white flower on a red flower tree.” Sri Ramakrishna answered confidently, “Yes, He can do everything — even that.”
The next day, on the way to the pine grove, Sri Ramakrishna saw two flowers, one red and the other dazzling white, on the same branch of a red hibiscus tree. He immediately broke off the branch and took it to Mathur. Naturally Mathur was amazed, and he said to Sri Ramakrishna, “Yes, Father, I am defeated.” (Source: They Lived with God)