I Ching, Yijing or Zhou Yi
"Oracle of the moon": © 2000 LiSe
What does it mean, 'inner' and 'outer trigram' (popup)
Zhèn below Gèn: the force of life within the body or in anything which 'lives', which makes things grow and keeps them healthy. It means both physically and mentally that one has to find the right food, nurturing and healthy, and enough of it. 'Living' is a wide concept: a book, an opera, an enterprise, a thought, or even a gesture towards someone, all these things need or bring food, all can be nurturing.
Ideogram of the hexagram name: at left a chin, and at right a big head, later a person with a big head with an eyebrow (emphasis on facial features). It means chin, cheek, maintenance, nourish, rear, care for, take care of oneself. Care has to do with healthy limits, the right dose of things. Jie yi (jie is the name of hex.40) is laugh or smile ('release jaw'). A tight jaw means anger or severity (at right an old character: jaw with teeth, sidewise).
The 'Great Image' says: Thunder at the foot of the mountain: jaws. The noble one uses cautious language and limited food and drink.
Hex.27 is the contrast of 28, which is about too much, excess, trespassing.
Hex.27 is avoiding excess, 'taking care' means finding a healthy way, both physically and mentally.