The judgment
大壯：利貞。
Great power. It is favorable to stay true: strength is only useful when it is restrained.
Received text; plain English after the Chinese. Source: 周易經傳 (public-domain). Passage: hex34.judgment.
The image
象曰：雷在天上，大壯。君子以非禮弗履。
Thunder in the sky: great power. A capable person does not step on what is improper.
Received text; plain English after the Chinese. Source: 周易經傳 (public-domain). Passage: hex34.image.
Power is measured by what it refuses to do.
The six lines
Each line is a stage, from the bottom of the hexagram to the top. Open any line to read it in plain English.
初九 壯於趾，征凶，有孚。 Strength in the toes: marching now brings misfortune. Sincerity is there, but the position is too low.
Strength in the toes: marching now brings misfortune. Sincerity is there, but the position is too low.
九二 貞吉。 Stay true and it is lucky. The middle line has strength and does not need to show it.
Stay true and it is lucky. The middle line has strength and does not need to show it.
九三 小人用壯，君子用罔，貞厲。 羝羊觸藩，羸其角。 A petty person uses force; a capable one uses restraint. Holding on is dangerous: the ram charges the fence and gets its horns stuck.
A petty person uses force; a capable one uses restraint. Holding on is dangerous: the ram charges the fence and gets its horns stuck.
九四 貞吉悔亡，藩決不羸，壯於大輿之輹。 Stay true, regret disappears. The fence opens and the horns come free; strength is in the axle of the great cart, not the horns.
Stay true, regret disappears. The fence opens and the horns come free; strength is in the axle of the great cart, not the horns.
六五 喪羊於易，無悔。 Losing the ram in the easy field. No regret: letting go of the fight is cheaper than winning it.
Losing the ram in the easy field. No regret: letting go of the fight is cheaper than winning it.
上六 羝羊觸藩，不能退，不能遂，無攸利，艱則吉。 The ram charges the fence, can neither back up nor get through. Nothing is gained; if you can endure the difficulty, it turns lucky.
The ram charges the fence, can neither back up nor get through. Nothing is gained; if you can endure the difficulty, it turns lucky.