大乘起信論裂網疏 6.60

6.60

If one has not planted roots of goodness, then even the mere name of this samādhi cannot be heard, let alone being able to cultivate it. To be able to cultivate this, one should know that this person must possess roots of goodness. However, if their roots of goodness were deep and thick, those demonic events would have no way to arise. It is like the sun disk high in the sky: there will certainly be no mountain sprites or ghosts. It is because roots of goodness are slight and few that demonic disruption is brought on; this is why the previous text exhorted one to cultivate the five repentances.