《太平广记·卷五·神仙五》
天门子由于按这些道理去修身养性。所以活到二百八十岁面貌仍然像童子少年。
天门子既行此道，年二百八十岁，犹有童子之色。
Tianmenzi cultivated his mind and nature by these rules, so he was still as young as a child at the age of 280.
<s>[INST] Convert the following English text into Classical Chinese: Tianmenzi cultivated his mind and nature by these rules, so he was still as young as a child at the age of 280. [/INST] 天门子既行此道，年二百八十岁，犹有童子之色。</s>
Convert the following English text into Classical Chinese: Tianmenzi cultivated his mind and nature by these rules, so he was still as young as a child at the age of 280.
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天门子既行此道，年二百八十岁，犹有童子之色。
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