首楞嚴義疏注經 9.301

9.301

此貪欲種如火遇薪，忽然而發，欲魔得便因此入心。如林中比丘忽然禪發，不避死馬，因定引魔，此之類也。攝諸凡愚至千萬者，欲本順貪，因魔熾盛，凡愚惑著何事不從？又魔因妄起，本性不常，勢盡厭生，去身留難。

These seeds of greedy desire are like fire meeting firewood: suddenly flaring up, the demon of desire finds an opening and thereby enters the mind. It is like the bhikṣu in the forest who suddenly experienced a meditative breakthrough and did not avoid the dead horse—drawing demons on account of concentration; it is of this kind. As for gathering ordinary and foolish people up to tens of thousands: desire fundamentally accords with greed, and flaring up because of the demon, what would the deluded and attached ordinary fools not comply with? Furthermore, because demons arise from delusion, their fundamental nature is not permanent; when their power is exhausted and weariness arises, they abandon the body and leave behind disaster.