Mahāyāna Sūtra of Revealing Consciousness (86)

Original text:贤护。其为富丹那等。下恶鬼神。之所著者。便爱粪垢。腐败涕唾。诸不净物。以此祭解。欢喜病愈。其人以鬼神力。随鬼神欲。爱乐不净。臭朽粪秽。识以罪资。亦复如是。或生贫穷。或生饿鬼。及诸食秽。畜生之中。种种恶趣。由罪资识。身获苦果。

Explanation: The Buddha said, Bhadrapāla, if a person is possessed by inferior evil ghosts and spirits such as the Fudana, this sentient being will come to love filthy, dung-covered places, places that are rotten and foul-smelling, with mucus and saliva, and will delight in unclean things such as mucus and saliva. If these unclean things are used in offerings to appease the ghosts and spirits, this person's illness and suffering will disappear, because the ghosts and spirits can repay this person by using their supernatural powers to cure his illness. Those evil ghosts of meager merit (alpa-puṇya) will even scramble for a single spit of phlegm from a person; saliva is a delicacy for ghosts and spirits, mucus is also a delicacy for ghosts and spirits, and in dung-covered places there are also ghosts without merit that come to devour the filth. These ghosts and spirits of meager merit all received this retribution because, when they were alive as humans, they were unwilling to practice generosity (dāna) and were miserly by nature. If a person is controlled by ghosts and spirits, then whatever the ghosts and spirits want to do through him, he does; whatever the ghosts and spirits like, he likes, because his mind has been controlled by the ghosts and spirits and he can no longer act of his own volition. When sentient beings create karmic offenses, the seeds of those offenses are stored in the Ālayavijñāna, and the sentient beings manifested by the Ālayavijñāna are just like this—loving lowly, degraded, filthy places covered in dung and filth. Because this person did not cultivate merit, there is no meritorious karma in his Ālayavijñāna—only karmic offenses—so this sentient being is either born into a poor family, or born into the realm of hungry ghosts where he devours foul and filthy things, or born into the animal realm, where animals likewise eat nothing but filthy food and drink. Being born among these three evil destinies is all the result of the Ālayavijñāna being nourished by karmic offenses; the Ālayavijñāna then causes his five-aggregate (pañca-skandha) body to reap such bitter retributive fruits of offense.