Two lakes side by side: a hexagram of gladness that goes through when firmness holds the center, with a warning against pleasing by false means.
Both trigrams are Dui ☱, the lake, whose quality is joy; in the family it is the youngest daughter. Zhu Xi sees one yin line that has come out above two yang lines, gladness showing itself on the outside. Firm at the center and soft outside, gladness goes through, but false pleasing must be guarded against, so the text adds that it is fitting to stay correct and firm.
Judgment (卦辭)
The text attached to the whole hexagram, read when no line is changing.
兌，亨，利貞。
Dui: success. It is fitting to be correct and firm.
兌 means gladness. Its image is the lake, which gladdens all things; Zhu Xi also sees in its shape the water trigram with the outlet at the bottom closed off. Firm lines at the center and a soft line outside: firmness within lets gladness go through, while softness outside makes correctness necessary, because gladness won by false means must be guarded against. He allows a second reading as well, in which the soft outside brings the gladness and success and the firm center the correctness.
Image (大象)
The Image commentary (象傳) reads the whole hexagram from its two trigrams.
麗澤，兌。君子以朋友講習。
Lakes joined together: Dui. The noble person, accordingly, studies with friends, talking things through and practicing together.
Two lakes side by side keep each other replenished. Zhu Xi sees in this the picture of friends who discuss and practice together, each adding to what the other has. It is a gladness that enriches both sides.
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
和兌，吉。
Gladness in harmony. Good fortune.
A yang line in the trigram of gladness, at the very bottom, with no ties to any correspondent: its gladness is harmonious and attached to no one in particular. Zhu Xi says this position gives both the image and the verdict. Pleasure without private ties is the kind the text approves.
Line 2, yang (九二)changing line in the shared reading
孚兌，吉，悔亡。
Gladness grounded in sincerity. Good fortune. Regret vanishes.
For Zhu Xi, firmness at the center means sincerity, and sitting in a yin place is what would cause regret. If one's gladness rests on sincerity, there is good fortune and the regret vanishes. Gladness of this kind is the opposite of the false pleasing the judgment warns against.
Line 3, yin (六三)changing line in the shared reading
來兌，凶。
Gladness that comes seeking. Misfortune.
Soft, neither central nor correct, the third line is the ruler of the lower trigram of gladness. It has no correspondent above, so it turns back to the two yang lines below to seek pleasure from them, which Zhu Xi calls the way to misfortune. Gladness sought from others, rather than shared with them, is what the text faults here.
Line 4, yang (九四)changing line in the shared reading
商兌未寧，介疾有喜。
Weighing what to be glad in, not yet at rest. Standing firm and spurning what is crooked, there is cause for joy.
Above, the fourth line serves the central, correct fifth; below, it is next to the soft, crooked third. Torn between them, it deliberates and cannot settle. But its nature is firm yang, so it can hold resolutely to what is right and turn away from the crooked line, and then there is joy. Zhu Xi notes that the warning in this line runs deep.
Line 5, yang (九五)changing line in the shared reading
孚于剝，有厲。
Placing trust in what strips away. There is danger.
剝 means the yin that can strip away yang. The fifth line is firm, central and correct, but in a time of gladness, in the seat of honor, it sits right next to the top line, the yin at the height of gladness that can please falsely and wear the yang down. So Zhu Xi reads the line only as a warning: to trust the top line is dangerous.
Top line, yin (上六)changing line in the shared reading
引兌。
Drawing others into gladness.
As the ruler that completes the gladness, the top line is yin at the height of pleasure, drawing the two yang lines below to share it, though it cannot make sure they will follow. That, Zhu Xi explains, is why the warning is placed on the fifth line and this line names neither good fortune nor misfortune.
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.