高僧傳 12.64

12.64

論曰：諷誦之利大矣，而成其功者希焉。良由總持難得，惛忘易生。如經所說，止復一句一偈，亦是聖所稱美。是以曇邃通神於石塢，僧生感衛於空中，道冏臨危而獲濟，慧慶將沒而蒙全。斯皆實德內充，故使徵應外啟。經云：「六牙降室，四王衛座。」豈粵虛哉？若迺凝寒靖夜，朗月長宵，獨處閑房，吟諷經典，音吐遒亮，文字分明。足使幽靈忻踊，精神暢悅。所謂歌詠誦法言，以此為音樂者也。

The evaluation says: The benefit of chanting and recitation is vast indeed, but those who bring it to fruition are few. This is truly because dhāraṇī is difficult to attain, while dullness and forgetfulness easily arise. As the sūtras explain, even a single phrase or a single verse is praised by the sages. Thus did Tansui spiritually communicate at the stone dock, Shengsheng invoke protection in the open sky, Daojiong obtain rescue in the face of peril, and Huiqing receive preservation when on the verge of drowning. In all these cases, genuine virtue was filled within, so that evident responses were manifested without. As a sūtra says, "The six-tusked [elephant] descends to the chamber, and the Four Heavenly Kings guard the seat." How could this be spoken in vain? When the chill condenses on a tranquil night or under a bright moon during a long eve, dwelling alone in a secluded room, chanting and intoning the scriptures with a voice vigorous and clear, each word and character distinct—this is enough to make the hidden spirits leap for joy and refresh the consciousness. This is what is meant by singing and chanting the words of the Dharma and taking this as music.