When he was governor of Hang province, he studied with Zen Master Daolin of Niaoke.
One day Zhuyi said, "What is the essential meaning of the buddha dharma?"
Daolin said, "Refrain from unwholesome action, do wholesome action."
Zhuyi said, "If that is so, a three-year-old child could say it."
Daolin said, "A three-year-old child may say this, but even an eighty-year-old person cannot practice it."
Zhuyi bowed in gratitude and left.
---Master Dogen, in Shoaku Makusa---