Just as the sun gives light to the moon the heart lights the mind.–Maharishi Ramana.
Comment; It is very important to understand that Maharish Ramana was an enlightened sage who got this knowledge by not studying from any scripture or go on the feet of an enlightened saint he found the experience by God’s grace or from last lives of good Karmas. That is why I choose for meditation a perfect sage from the 20th century. Because he used to speak from his spiritual experience.
Our mind is not perfect it has no, its own light. It takes light from self or God. Body, mind, or senses take light from Observer or self. Who have reached into the depth of self they said that you are not body and mind.
One time in life of Maharishi Ramana, he was going on a walk with some devotees, he felt some pain in the chest and he sat down and his body starts to become dark and devotees start to cry, he told after this that he was watching that his body is going to be darker and darker and he was aware if this happening and his body was laying dead and his devotees were weeping. After some time I felt that the body starts to move and I sat down and then I told my followers that it is a body which dies but due to the illusion we think that we are the body. Meditation is for this purpose that you can understand. I am not body and mind. According to Vadanta we have to figure out that we are self. That is why we say self-realization.