It is an old cliche, usually expressed with the intent to ‘cheer’ someone up. A friend or family member is going through a hard time and these words are spoken from separation. This sense of separation, of being away from the light, is only a thought. In reality, you are the light at the end of the tunnel. Where else could the light come from, but you?!
Your being lights up this tunnel. Only the mind decides if it is a narrow and confining prison or an all-encompassing heaven on earth. And the mind is irrelevant; no matter what comment it makes about reality, it does not change it at all. Only appearances come and go, but you, in fact, never come and go. You are always here.