摩訶止觀 8.130

8.130

夫眾生實疾從癡愛生，癡愛纔生大悲亦起；癡愛纔滅大悲亦滅。眾生有愈、有不愈，菩薩有疾、有不疾。若無疾者，知其子愈；若有疾者，化道未休。故方丈問疾、茅城背痛，皆此義也。誓願既等虛空，有疾亦彌法界，是名「不思議慈悲」也。慈悲力大，菩薩適發此心，疾即除愈，不俟更修下法。法喜、天台（云云）。若發心不真，欺眾生、要三寶，有所規求，病亦不差。若能真誠，有大勢力。

Sentient beings' actual illness arises from delusion and attachment; as soon as delusion and attachment arise, great compassion also arises; as soon as delusion and attachment are extinguished, great compassion is also extinguished. Sentient beings may be cured or not cured; bodhisattvas may be ill or not ill. If [the bodhisattva] has no illness, one knows their child is cured; if they have illness, their path of conversion has not ceased. Therefore, the inquiry after the illness in the ten-foot room, and [the Buddha's] back pain at the city of thatched huts, both have this meaning. Since the vow is equal to empty space, having an illness also permeates the dharmadhātu; this is called "inconceivable loving-kindness and compassion." The power of loving-kindness and compassion is great: as soon as a bodhisattva gives rise to this mind, the illness is immediately cured, without waiting to practice the further methods below. Faxi and Tiantai (and so forth). If the arousal of the mind is not genuine, deceiving sentient beings and seeking from the Three Jewels with ulterior motives, the illness will not be cured. If one can be sincere, it possesses great power.