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A child at a temple gate can recite sutras they've never been taught.
Literal
Gate-front [gen-の] young-monk unlearned sutra [obj-を] reads.
A famous 諺 (proverb): 門前の小僧習わぬ経を読む ('the acolyte at the temple gate reads sutras he hasn't learned'). It means that constant exposure leads to learning even without explicit instruction — the equivalent of 'a child raised on the water learns to swim' or 'by rubbing shoulders with X, you absorb it.' 小僧 is a young temple attendant; 経 is a Buddhist sutra. 習わぬ is the classical negative form of 習う.