Fire beneath a lake, each undoing the other: a hexagram of change that wins trust only after its day is past, and succeeds when what is changed is right.
The upper trigram is Dui ☱, the lake, whose quality is joy; the lower is Li ☲, fire, bright and clinging. Zhu Xi notes that fire dries up water and water puts out fire, and that the two daughters here, the youngest above and the middle one below, have aims that do not agree, so the hexagram stands for change. Bright within and harmonious without, a change made rightly goes through greatly.
Judgment (卦辭)
The text attached to the whole hexagram, read when no line is changing.
革，已日乃孚，元亨，利貞，悔亡。
Ge: only when the day is past is there trust. Great success. It is fitting to be correct and firm. Regret vanishes.
At the outset of any change, Zhu Xi says, people do not yet trust it; only once its day has passed do they come to believe in it. The lower trigram brings inner brightness and the upper an outward air of harmony and joy, so whatever is reformed goes through greatly and attains what is right, and when every change is fitting, the regret that change brings vanishes. He adds the converse: if anything in it is not right, the change is neither trusted nor carried through, and regret returns instead.
Image (大象)
The Image commentary (象傳) reads the whole hexagram from its two trigrams.
澤中有火，革。君子以治歷明時。
There is fire in the lake: Ge. The noble person, accordingly, works out the calendar and makes the seasons known.
Fire and water held in one place, each working against the other, give the image of change. Zhu Xi notes simply that the turning of the four seasons is the greatest of all changes; keeping the calendar and making the seasons clear is how the noble person answers it.
Lines (爻辭)
From the bottom line to the top. In the line names, nine (九) marks a yang line and six (六) a yin line.
Line 1, yang (初九)changing line in the shared reading
鞏用黃牛之革。
Bound fast with the hide of a yellow ox.
Although it is a time for change, the first line (初九) sits at the very bottom with no correspondent, so it cannot yet act. 鞏 means to bind fast; yellow is the color of the center, the ox a docile animal, and hide (革, the hexagram's name in another sense) binds things tight. The text calls for holding firm, not acting, and Zhu Xi sees here how cautious the sages were about change.
Line 2, yin (六二)changing line in the shared reading
已日乃革之，征吉，无咎。
When the day is past, make the change. Going forward brings good fortune. No blame.
Yielding, central and correct, the second line is the ruler of the bright lower trigram and has a correspondent in the fifth line. It is in a position to carry out change. Even so, the change should come only once the day is past; then going forward is favorable and blameless. Zhu Xi reads this as a warning not to change abruptly, even when everything seems ready.
Line 3, yang (九三)changing line in the shared reading
征凶，貞厲。革言三就，有孚。
Pressing forward brings misfortune; even holding correct and firm is dangerous. When talk of change has been settled three times, there is trust.
Too firm and off-center at the top of the fire trigram, this line is restless and eager to change things. Hence the double warning: pushing ahead brings misfortune, and even firm correctness is in danger. Yet the time does call for change, so once the talk of reform has been settled three times, it gains trust and can go ahead. The line sets impatience against the slower work of winning agreement.
Line 4, yang (九四)changing line in the shared reading
悔亡，有孚改命，吉。
Regret vanishes. There is trust. Altering the mandate brings good fortune.
A yang line in a yin place would normally bring regret. But the hexagram is past its midpoint here, where the fire below meets the water above: the very moment for change. Firmness tempered by a soft position is also the right tool for change, so regret vanishes. Still, Zhu Xi insists, there must be trust before the change brings good fortune; the right quality, the right time and credibility have to come together.
Line 5, yang (九五)changing line in the shared reading
大人虎變，未占有孚。
The great person changes like a tiger. Even before divining, there is trust.
The tiger stands for the great person; its change, Zhu Xi explains, is the coat thinning and coming in sleek and new. In the great person it means renewing oneself and the people to the utmost, in accord with heaven and in response to humankind. The fifth line, firm, central and correct, rules the reform. Zhu Xi adds a condition: the line fits only someone people already trust before any divination is made.
Top line, yin (上六)changing line in the shared reading
君子豹變，小人革面。征凶，居貞吉。
The noble person changes like a leopard; the petty person changes face. Going forward brings misfortune. Staying put, correct and firm, brings good fortune.
With reform complete, the noble person is transformed like a leopard's coat, and even the petty change their outward face and fall in line. Zhu Xi explains why one should go no further: change is undertaken only when unavoidable and must not be overdone, and this weak top line lacks the strength to act anyway. So the text favors staying put and keeping correct; knowing when a change is finished belongs to the change itself.
If you drew this hexagram
Which text to read depends on how many lines are changing. With none, read the judgment; with one, read that line; with more, follow Zhu Xi's rules in the Yixue qimeng.
Text: Zhu Xi, Yuanben Zhouyi benyi (原本周易本義), Siku Quanshu Wenyuange copy, as transcribed by the Kanseki Repository (KR1a0031), corrected and punctuated by K-magpie. Translation and explanation: written by AI (Claude) from Zhu Xi's commentary and checked against the text and commentary. Sources and the list of corrections are on the Today's Hexagram page.