金剛三昧經論 2.142

2.142

經曰　大力菩薩言：「云何二入不生於心？心本不生，云何有入？」佛言：「二入者，一謂理入、二謂行入。理入者，深信眾生不異真性，不一不共，但以客塵之所翳障。不去不來，凝住覺觀，諦觀佛性不有不無，無己無他、凡聖不二，金剛心地堅住不移，寂靜無為、無有分別，是名理入。」

The sūtra says: Mahābalavān Bodhisattva said, 'How is it that the two entries do not produce mind? The mind fundamentally does not arise; how can there be entry?' The Buddha said, 'As for the two entries: the first is called entry through principle; the second is called entry through practice. Entry through principle means deeply having faith that sentient beings are not different from true nature, neither one nor combined, but merely obscured and blocked by adventitious dusts. Neither departing nor arriving, one abides steadily in awareness and observation, clearly contemplating that buddha-nature is neither existent nor nonexistent, without self and without other, ordinary beings and sages not being two; the vajra-mind ground firmly abides without moving, tranquil, unconditioned, without discrimination—this is called entry through principle.'