What this hexagram is about
Thunder bursts forth from the earth, rousing and harmonious — the image of joy and ease. Yet within contentment one must foresee danger and stay prepared; move with the momentum of things, but never sink into mere pleasure.
The Judgment 卦辞
豫，利建侯行师。
It is favorable to install helpers and set the army marching.
The Image 大象传
《象》曰：雷出地奋，豫；先王以作乐崇德，殷荐之上帝，以配祖考。
Thunder bursts from the earth in rousing power; so the ancient kings made music to honor virtue, offering it in splendor to God and to their ancestors.
Commentary on the Lines 小象传
初六鸣豫，志穷凶也。
Proclaiming one's enthusiasm at the start — the will is spent, and there is misfortune.
The Six Lines (hover over the figure above)
Nine at the top冥豫，成有渝，无咎。
Steeped in pleasure to the point of utter blindness; yet should one wake with a start and change one's course, there may still be no fault.
Six in the fifth place贞疾，恒不死。
Long beset by care and danger, like a lingering illness, yet one is kept from ruin after all — for a measure of dread becomes one's safeguard.
Six in the fourth place由豫，大有得。勿疑，朋盍簪。
When the joy of the many looks to him to lead it, much is gained. Harbor no suspicion, and friends gather to one as hairpins drawn together.
Six in the third place盱豫，悔。迟有悔。
To seek one's joy by flattery, hanging on another's favor, will bring remorse; to waver and not mend it only deepens that remorse.
Six in the second place介于石，不终日，贞吉。
Firm as a rock, content yet not steeped in pleasure; before the day is out one reads the faint first signs and settles oneself in time — holding to what is right, good fortune.
Initial Six鸣豫，凶。
To lose oneself in self-satisfaction and parade one's joy — misfortune.