[A]s we ask where do hell and the Buddha exist, some sūtras state that hell exists underground while others state that the Buddha exists to the west. Upon closer inspection, however, it is preached that both hell and the Buddha exist within our five-foot bodies. As proof of this, we sometimes disdain our fathers or neglect our mothers in our minds. This indicates that our minds contain the function of hell. It is like the seed of the lotus plant that contains both the flower and the fruit. The Buddha also stays in our minds. It is like the fire that exists within a flint and the fortune that can be found within a gem. We ordinary people cannot see our own eyelashes, which are too close, or the end of the sky, which is too far. Likewise, we are unaware of the Buddha residing in our own minds.

Omonsu-dono Nyōbō Gohenji, A Reply to the Wife of the Lord of Omonsu, Writings of Nichiren Shōnin, Volume 7, Followers II, Pages 109