。
You must not break the law.
Literal
Law [object-を] violate-[must-not-てはいけない]
Classic short example of ~てはいけない prohibition. 犯す (to violate, commit) is used for laws, rules, and crimes — not 'to break' in a physical sense (which would be 壊す). Subject is omitted; the implied addressee is 'you' or 'one'.