Again, it is the meaning of the middle path. This is the reason why we recite the ten factors three times in the Hoben Chapter today when we are reciting Gongyo. T'ien-t'ai uses the simile of a mirror to explain the threefold truth. This simile is very popular among Buddhist scholars even today. The mirror itself signifies the middle truth.
Nothing reflected in the mirror means the emptiness truth.
Something reflected in the mirror stands for the conventional truth. I have now explained the outline of the concept of the threefold truth developed through the deep wisdom and insight of T'ien-tai the Great. This threefold truth is the integrated aspect of the ultimate truth of reality. I sincerely hope that you will grasp the outline of the threefold truth concept by reading the above statements of T'ien-t'ai the Great. In relation to the threefold truth, its practice and its resultant enlightenment, T'ien-t'ai proposes a simultaneous, a spontaneous and an immediate contemplation on the threefold truth.