If Dà Zhuàng has appeared in your reading, the book is naming a configuration of significant strength that has accumulated and is now ready to act. Four yang lines rising from below have broken into the upper trigram of Thunder. The hexagram appears when the reader genuinely has the power to do the thing in question — and the work shifts from gathering to choosing.

Classical commentary reads this hexagram as the test of restraint at the moment when restraint is hardest. When strength is incomplete, holding back is automatic. When strength is full, holding back becomes a discipline. The book is unsentimental: full power is dangerous to those who hold it and to those nearby it, and the test is what one does with it in the first hour of having it.

What the book counsels is captured in the strange line of the image: 非禮弗履 — do not step in any place that is not proper. The judgment is brief because the principle is brief. When you can do almost anything, do only what fits. The clearance 利貞 — fitting, upright — is conditional on this. Strength wielded without measure is not the hexagram's clearance; it is the hexagram's warning.

Dà Zhuàng's failure mode is the use of the strength simply because it is there. The book is alert to it. The hexagram appears when the reader has come into substantial capacity — political, financial, creative, physical — and the temptation is to demonstrate the capacity rather than to deploy it. The book is asking for the more difficult discipline: have the power, and act only where the acting fits.