大乘起信論義記 3.243

3.243

復次，顯示從生滅門即入真如門。所謂推求五陰色之與心，六塵境界畢竟無念，以心無形相，十方求之終不可得。

'Furthermore, it demonstrates entering the gate of tathatā directly from the gate of arising and ceasing. That is to say, when one investigates the five skandhas—matter and mind—the objects of the six dusts are ultimately without thought; because the mind has no shape or mark, seeking it throughout the ten directions, it is ultimately unobtainable.'