注大乘入楞伽經 9.127

9.127

或又云凡呪文自古不翻有五意：一是諸佛祕密語法，唯佛能知；二是總持門，含多義故；三或是鬼神名，呼之勅以守護修行人故；四或是諸佛祕密印，如王印信所往無不遵奉；五不思議力所加持故，受持密誦滅罪生福。此與天台意同異可知。

Or it is also said that from ancient times incantation texts have not been translated for five reasons: first, they are the secret Dharma words of the Buddhas, which only Buddhas can know; second, they are dhāraṇī-doors, because they contain many meanings; third, they are names of ghosts and spirits, called upon and commanded to protect practitioners; fourth, they are the secret seals of the Buddhas, like a king's seal of authority, which wherever it goes is obeyed; fifth, because they are empowered by inconceivable strength, upholding and reciting them secretly eliminates transgressions and generates merit. The similarities and differences between this and Tiantai's intent may be known.