佛祖統紀 3.138

3.138

祕密三義。籤云。須知密祕語同意別（云云）。今列諸文具出三義。一者真祕。玄云。法華是祕密。籤云。是祕妙之密。二者隱祕。自有佛弟子二義。玄引經云。四十餘年祕而不說。此昔所未談。約如來為祕也。妙樂云。三周之中。自論祕者。法說周時。密聞大車。此謂上周根利。預了譬喻因緣之事。對中下未悟。名之為密。此密有所聞。約弟子為祕也。三者祕密。即妙玄所立祕密教。如來隱密赴機互不相知者。籤云。是隱密之密。

The three meanings of secret: The Qian says: 'One must know that the words "mi" and "bi" share the same meaning but have different references' (and so on). Now, citing the various texts, three meanings are fully set forth: First, true secrecy. The Xuan says: 'The Lotus is secret.' The Qian says: 'It is the secrecy of the esoteric and wonderful.' Second, hidden secrecy. This inherently has two meanings, concerning the Buddha and the disciples: The Xuan cites the sutra saying: 'For more than forty years it was kept secret and not spoken.' This, being what was not discussed in the past, is secret with respect to the Tathāgata. Miaole says: 'Among the three cycles, when discussing secrecy within them: during the cycle of the Dharma expounding, they secretly heard of the great cart.' This means that those of sharp faculties in the upper cycle anticipated and understood the matters of parables and causes and conditions; in contrast to those of medium and lower faculties who had not yet awakened, it is called secret. Because this secret involved something heard, it is secret with respect to the disciples. Third, secret teaching: that is, the secret teaching established in the Miaoxuan, where the Tathāgata secretly responds to capacities such that they are mutually unaware. The Qian says: 'It is the secrecy of hidden concealment.'