涅槃經遊意 1.63

1.63

他明此經以常為宗，今初辨常者，乃倒寫之用，未是正意。常是藥用，豈會開正宗？前藥治前病，後藥治後病。常是藥用，常為宗者；無常是藥，亦應以無常為宗。

Others clarify that this sūtra takes permanence as its central tenet. Now, distinguishing permanence at the beginning is merely the function of inverting and purging; it is not yet the correct intent. Permanence is a medicinal function; how could it reveal the correct central tenet? Former medicine treats former illness, and later medicine treats later illness. If permanence is a medicinal function and permanence is taken as the central tenet, then since impermanence is also a medicine, impermanence should also be taken as the central tenet.