Yarrow, the most commonly used method of divination in the pre-Qin period, is also the earliest and most authoritative method of divination, and later generations call it "yarrow method".

(1): Tai Chi (take one).

(2): Three changes

Divide into two, hang one, four, and return to strangeness;

Divide into two, four, and return to strangeness;

Divide into two, four, and return to strange.

(3): Chu Yao

After the three changes are removed from the "return to the strange", the remainder is divided by four, that is, the first line.

Six (Lao Yin) and Eight (Shao Yin) are even numbers, which are Yin "--"; Seven (Shaoyang) and Nine (Laoyang) are odd numbers, which are yang "—".

(4): This hexagram

From the bottom to the top, the beginning, the second, the third, the fourth, the fifth, the sixth, and so on, the beginning of the hexagram.

(5): Change the hexagram

When dividing the hexagram, first seek the "original hexagram" through the yarrow method, and then seek the "change hexagram" through the variable line, so as to occupy the good fortune of the thing asked.

The idea of change is the core content of Zhanyi, and Zhanzheng is to seek the word through accidental change, so as to guide the maze and avoid evil.

The seven or eight or nine or six obtained by the yarrow method are seven or eight or nine or six, seven and eight are the unchangeable ones, and nine and six are the variable ones.

The ancients used seven and eight to symbolize spring and autumn, which were less yang and less yin; Nine and six symbolize summer and winter, respectively old yang and old yin.

The extremes of things must be reversed, and the prosperity of yin and yang must change, so it is changeable. Its change is every nine to six (every yang to yin), every six to nine (every yin to yang). Here, the first "nine" or "six" is the "original hexagram", and the following "six" or "nine" is the "change hexagram".

(6): Occupancy

A: If the six hexagrams are seven or eight, this hexagram is the same hexagram and can only be determined by this hexagram.

B: If each hexagram is nine or six, this hexagram is a hexagram of total change. If they are all nine, that is, they will be divided with the "use nine" of the hexagram; If they are all six, that is, they will be divided with the "use six" of the kun hexagram.

C: If there are nine and six, it is also a hexagram of total change, that is, nine changes to six, six changes to nine, so as to change the hexagram, and then use the "change hexagram" hexagram to account for it.

In short, the unchanging hexagram is used to occupy the hexagram with the "original hexagram"; The hexagram of full change, use the "change hexagram" hexagram to occupy the divination; It's just an exception.

D: If the variable hexagram is less than the unchanged hexagram, the hexagram "this hexagram" is used to occupy it; If there are more variable hexagrams than unchangeable hexagrams, the hexagram "changing hexagram" is used to occupy the decision; If the variable hexagram is equal to the unchangeable hexagram, the hexagram of "original hexagram" and "changing hexagram" is used to comprehensively occupy the hexagram.