Documented: Zhuangzi chapter 4, In the World of Men, stages Confucius instructing Yan Hui in xinzhai, fasting of the heart: hearing not with the ear or the mind but with qi, which is empty and waits for things. The line xu shi sheng bai, the empty room gives birth to white brightness, is the chapter's hinge. The text is in every Zhuangzi edition, Guo Xiang's included.
The reading the chapter itself insists on: emptiness here is not withdrawal but tact, the empty room is how you survive the court of a dangerous man. Zhuangzi's mysticism is aimed at navigating power, the brightness is situational intelligence, not halo. Later Chan and literati culture aestheticized it; the original is almost Machiavellian.
The exegetical debate: commentators argue whether the white brightness is clarity, spirit, or an actual luminosity experience, and the text refuses to say. The phrase's career in Chinese aesthetics, empty rooms in painting, blank silk as presence, is documented; whether Zhuangzi meant a vision or a disposition is the standing question.
What gathers in a mind that stops furnishing itself?