法華義疏 2.40

2.40

彼經明一切眾生失一道清淨故成種種道，諸佛無緣大悲欲令眾生歸於一道，是故從一道出無量教耳。

That sūtra explains that all sentient beings, having lost the purity of the One Path, consequently formed the various paths. The Buddhas, with unconditioned great compassion, wish to cause sentient beings to return to the One Path; therefore, from the One Path they bring forth the innumerable teachings.