大壯 → 小過

Commentary

Thunder above heaven sends the spring wild goose flying eastward — a migratory image of natural timing and directional instinct. Trading horses for gold, one obtains deep profit. The verse is compact and auspicious: the goose follows its season, the merchant follows his opportunity, and both arrive at abundance. Spring geese moving east signal renewal and the reliable return of warmth. From Great Power to Small Exceeding, thunder sits above the mountain in Xiaoguo: conduct slightly exceeds the norm, as in excessive reverence, excessive grief, excessive frugality. The transformation suggests that the profit here comes from a modest overstep — trading the large (horses) for the refined (gold), accepting a small excess that yields concentrated value. Power wisely contracted outperforms power broadly spread.