I have heard about a bone in the brain that never disintegrates. You can't burn it, break it or crush it. What is this bone called and what is its purpose?
The Aish Rabbi Replies:
The name of the bone is called the "Luz." It is about the size of a kernel of barley, and is located underneath the brain, on the top of the spine. Perhaps the most peculiar attribute of this bone is that it can never be destroyed, and it gains its sustenance from a meal eaten each Saturday night called "Melave Malka." In the future, resurrection of the dead will begin with this bone. (Sefer Ta'amei Haminhagim 425)
Why will the resurrection of the dead begin with this bone? Rebbe Nachman of Breslov explains that no matter how low a person has fallen, there exists an indestructible part in him, that can form the basis for a new resurrection – a new life.
We can apply this idea to our own quest for spiritual growth. Ask the Almighty to help you find that indestructible part, that essence of yourself that no mistake or misfortune can erase. Bind yourself to it. Concentrate on it. Then, even if you find yourself in the deepest, darkest pit without the slightest trace of hope or light – still, you will always find your way out. That is the power of the Luz bone.