Axle-straps of the carriage. The fourth line's firm Yang grows abundant and strong, having already passed the middle; its strength is profound. Yet dwelling in the fourth place, it is in an incorrect position.
At a time when the gentleman's Dao is on the rise, how could there be any lack of correctness? Hence it is cautioned that with perseverance there is good fortune and remorse disappears.
When the Dao is rising, even a slight lapse harms the momentum of prosperous advancement, which brings remorse. In other hexagrams, when doubled firmness dwells in yielding, it is not necessarily unfavorable—hexagram Da Guo is an example.
A hedge is that which restricts and divides; when the hedge breaks open, its strength is no longer entangled and distressed.
When the wheel axle-straps of a tall, great carriage are strong, the benefit of its travel can be known; hence it says 'strength in the axle-straps of a large carriage.'
The axle-straps are the crucial part of the wheel; the breakdown of a carriage usually lies in broken axle-straps. When the axle-straps are strong, the carriage is sturdy. Saying 'strength in the axle-straps' means being strong in advancing. Fù is the same as fú.
The Xiang Commentary says: 'The hedge breaks open and there is no entanglement; it still advances.' The growth of firm Yang must reach its extreme. Although the fourth line is already flourishing, its advance has not stopped.
Advancing with strength through the utmost flourishing Yang, nothing can withstand it; the hedge breaks open and does not entangle or distress its strength. 'It still advances' means its advancement is ceaseless.