Sri Chinmoy: Spiritual Masters can postpone it indefinitely if it is God’s Will. A spiritual person gets this power when he has attained to spiritual Perfection, because then he is absolutely surrendered to God. A disciple comes to a Guru and surrenders entirely to him. Similarly, a Guru has to make absolute surrender to God the Infinite. In this surrender he becomes one with God. He does not break the Law of God; he only tries to fulfil it. If God says, “I want you to leave the body now,” he leaves the body. But if he sees that some hostile forces are attacking him and are untimely causing his death, then he uses his power because God wants him to live on earth to help humanity.
Having this power is of no use if you just want to stay on earth for two or three hundred years to live an ordinary animal life. A turtle lives for hundreds of years, but that does not mean that it is better than a human being. What we need is direct illumination, the knowledge of Truth, the knowledge of Light and the knowledge of God. It is not the years, but the achievements, that count.