大乘起信論略述 1.142

1.142

論。是故一切至唯心虛妄　述曰。此顯境體亦無也。如鏡中像無實體故鏡外鏡內皆不可得。境但是心虛妄現故心外心內無體可得。

Treatise: Therefore, all... are only mental falsities.
Commentary: This shows that the essence of the realms is also non-existent. Just as an image in a mirror has no real essence, so it cannot be found either outside or inside the mirror; because sense-realms are only the deluded manifestation of the mind, no essence can be found either outside or inside the mind.