The highest number in Chinese numerology is 9, which is often associated with the Heart. In addition to the numbers 5 and 12 in symbolic categorization of phenomena, according to numbers, 9 plays an important role in ancient Chinese cosmology. 9 is the number symbolic from which all else transpires. Sacred books such as the Tao te Ching and the Huangdi NeiJing were often written in 81 chapters [i.e. 9 x 9],  indicating that the content of said book is inspired by a Heavenly source and descriptive of Heavenly measures. In medical texts, there are occasional references to a resonance between the 9 provinces on Earth [Jiu Zhou] and the 9 orifices of humans [Jiu Qiao].  -Heiner Fruehauf

If you wish to read the relevant passage in context, an excellent [and the only complete] English translation is published, ‘The Huainanzi.’: http://cup.columbia.edu/book/978-0-231-14204-5/the-huainanzi. Interestingly, the somewhat enigmatic term Jiu Jie, or the Nine Regions of Heaven, is only used once in ancient Chinese literature, namely this passage from The Huainanzi. Most traditional commentators of this passage mention that the number 9 refers to the 8 directions of the bagua, accounting for the center.