This article records tradition as it has been passed down and reported. Its sources are not yet part of the atlas's verified catalogue.
Before he became the teacher known for delivering Zen in everyday spoken Japanese, Bankei spent his early twenties in an extreme ascetic seclusion of his own devising, building a hut and sitting in meditation for as many hours a day as his body could bear, having given up ordinary comfort with no goal besides forcing a breakthrough, a documented early practice distinct from the plain-speech public teaching his first article covers. Around age twenty four that regimen brought on a severe illness, likely tuberculosis, and the physician attending him reportedly expected he would die of it, a documented medical crisis distinct from anything in the settled teaching career that followed.
At the height of that illness, according to his own later account of the episode, Bankei felt a strange sensation in his throat, spat a mass of dark phlegm against the wall of his sickroom, and in the instant of watching it roll down realized that all things are perfectly resolved in the unborn, a documented account of his enlightenment distinct from any doctrine he later delivered as settled teaching. His doubts ceased at that moment and his health began to turn, a documented recovery distinct from the decades of public instruction the breakthrough eventually produced.
That the teacher remembered for making Zen accessible to tens of thousands of ordinary listeners in plain speech first reached his own central teaching, that everyone already possesses the Unborn and needs only to recognize it, through a self-imposed illness that nearly killed him, marks Bankei's sickroom breakthrough as a documented case where an insight built for public simplicity was purchased, in private, at considerable physical cost.