高僧傳 12.28

12.28

又佛說身有八萬戶蟲，與人同氣。人命既盡，蟲亦俱逝。是故羅漢死後，佛許燒身。而今未死便燒，或於蟲命有失說者。或言羅漢尚入火光，夫復何怪？有言入火光者，先已捨命。用神智力，後乃自燒。然性地菩薩，亦未免報軀。或時投形火聚，或時裂骸分人。當知殺蟲之論，其究竟詳焉。

Moreover, the Buddha taught that the body contains eighty thousand families of parasites, which share the same breath of life with the human. When a human's life ends, the parasites also perish. Therefore, only after an arhat dies does the Buddha permit the burning of the body. Now, burning before death may perhaps involve the loss of the lives of these parasites. Some might say: 'Arhats even enter the fire-samādhi; what is so strange about this?' To this it is replied that those who enter the fire-samādhi have first surrendered their lives, and using the power of spiritual wisdom, only afterward burn themselves. Yet bodhisattvas on the stages of nature are also not free from retribution bodies; sometimes they cast their forms into a mass of fire, and sometimes they tear apart their flesh to distribute to people. One must know that the argument concerning the killing of parasites has been treated with utmost thoroughness in the ultimate sense.