The Heavenly Gate is nonbeing. The ten thousand things come forth from nonbeing. Being cannot create being out of being; inevitably it must come forth from nonbeing. Nonbeing is absolute nonbeing, and it is here that the sage hides himself.
Zhuangzi posits nonbeing as the absolute cosmological ground — the Heavenly Gate — from which all existence necessarily proceeds, and in which the sage conceals himself.
, The Complete Works of Zhuangzi, 2013thesis