If Cuì has appeared in your reading, the book is naming a season of gathering. People, resources, attention, occasions are converging on a single centre. The lake rests above the earth — water has been drawn to where the ground accepts it. The hexagram appears when something is forming around the reader, or around something the reader is involved with, that has the gravitational shape of a coalescence.
Classical commentary reads this hexagram as the ritual aspect of community formation. The judgment's references to the temple, the great person, the great offering are not decorative; they name the seriousness with which gathering must be conducted to hold. The reader is being asked to show up, to commit, to bring the substantial offering — not the gesture, the real one.
What the book counsels is the doubled discipline of being present and of being prepared. The image is precise on this: 除戎器, 戒不虞 — renew the weapons, prepare for what is not yet foreseen. Wherever many gather, friction also gathers; resources collected attract those who would take them. The hexagram does not say this to discourage assembly. It says it so the assembly will be sound enough to last.
Cuì's failure mode is the lazy proximity that mistakes being near a gathering for being part of one. The book treats this as common. The hexagram appears when the reader is invited into something real and the temptation is to stay on the edge. The clearance — fitting to have a place to go — is for the reader who walks in and takes their part in the centre, with the right offering, in the right ceremony.