Jacob saw that the children who had fallen into the habit of depending upon him, were now worried as to what would happen to them if he was no longer available to help them. Their habit had to be broken right now if they were to stand on their own feet and face life directly. It was imperative that they became independent, free. Otherwise they would continue to depend upon one guru or another all their life, replacing such crutches periodically. So he narrated the story of the teacher and the student, hoping that they would get the point.
Even while meeting his death, the teacher in the story wanted to convey to his student that the light that a man discovers and carries within himself, is something that he cannot pass on to another, however much he may love him. He also wanted to make it clear that the student should not expect any help from anyone, but seek help only from his own self, where all the help necessary for man is available. Help from another person in this matter will be no help at all, but will only harm the individual, making him permanently depend upon someone and his spiritual authority. The student, on the other hand should be on his own, grow wings and go flying independently.
One will have to discover one's own light, and thus be a light unto himself. The light that the Buddha discovered was useful to him, but his light will not serve you. He moved from 'darkness' to light, but it was his darkness. You have your darkness, which is unique to you. And you have to work on it. You are plagued by your opinions, your prejudices, your likes and dislikes, which are not the same as another man's. So you will have to be aware of what is contained within you at the superficial and deeper levels, bring it out and see it for what it is.
When each facet of your darkness, also termed as ignorance, is brought out
and seen' in the light of awareness without identification, without justification
condemnation, it withers and dies. This is the light which dispels all darkness.
When you are such a light unto yourself, you don't depend upon anybody, you
follow no man. It is this kind of light which leads you step by step to the
far beyond.