妙法蓮華經文句 2.113

2.113

As for the origin and traces: originally, as the four kings of permanence, bliss, self, and purity, they protect and maintain the Buddha's Dharma so that outsiders do not seize its branches and foliage to chop down and destroy them. The King of Permanence protects the twin trees of permanence and impermanence in the east; the King of Bliss protects the twin trees of bliss and non-bliss in the south; the King of Self protects the twin trees of self and non-self in the west; the King of Purity protects the twin trees of purity and non-purity in the north. The branches and trunk represent permanence, the blossoms represent self, the fruits represent bliss, and the luxuriant leaves represent purity. Because protecting these blossoms and fruits can constantly benefit all sentient beings, in their traces they become the four kings to protect the world.