The Channel of Preservation joins the Sacral centre to the Spleen centre through Gates 27 and 50, and both of those numbers are borrowed. They are positions in the King Wen sequence of the I Ching, the Chinese divinatory classic whose sixty-four hexagrams Human Design maps one to one onto the sixty-four gates of its bodygraph. Read as I Ching rather than as Human Design, the two numbers name two independent oracle texts.
Hexagram 27, Nourishment (Yi). Thunder below the mountain, the shape of open jaws. It concerns what a person feeds and is fed by, watching both what goes into the mouth and what comes out of it.
Hexagram 50, The Cauldron (Ding). Fire flaming above wood. The ting is the vessel of sacrifice and of cooked nourishment, the hexagram of culture consecrating the material and nourishing the worthy.
The I Ching itself never sets these two hexagrams in a pair. Each stands alone in the sequence, consulted about a changing situation and answered in counsel that passes. The pairing is a construction of Ra Uru Hu's system, published from 1987, which fixes each hexagram to a position in a birth chart and reads the joined pair as a lasting trait of the person. The correspondence of number is real, and both hexagrams can be followed into their own entries in this atlas; the pairing, and the character read out of it, belong to the modern system alone.