大乘起信論略述 2.87

2.87

論。以心無形相至終不可得　述曰。下顯觀心。於中有三。謂法喻合。此初也。六塵色法多現有像尚不可得。況心無形像而可得耶。由無形故即無住處。無住處故即無所有。故言十方求之終不可得。

[Treatise:] Because the mind has no bodily form ... in the end can never be found.
[Exposition:] Next, revealing the contemplation of the mind. In this there are three: the doctrine, the simile, and the application. This is the first. Even the form-dharmas of the six sense fields, which mostly appear with shape, cannot be found; how much less can the mind, which has no bodily shape, be found? Because it has no form, it has no abiding place; because it has no abiding place, it is non-existent. Hence it says, "seeking it in the ten directions, in the end it can never be found."