The source of this book comes from Liu Xiang's Talking about Yuan Jianben.
Duke Jinping asked Shi Kuang, "I am seventy years old, but I still want to study. I am afraid it is a bit late! "
Shi Kuang said, "Why don't you light a candle?"
Duke Ping of Jin said, "How can a minister joke with the monarch casually?"
Shi Kuang said, "I am a blind minister. How dare I joke with you? I heard that when I was young, it was easy to learn, just like the sunrise in the morning; When you are in the prime of your life, you are eager to learn, just like the sun rising to the sky; Being old and eager to learn is like lighting a candle. Isn't lighting candles much better than walking in the dark? "
Jin Pinggong said, "That's right!"