Hongzhi was the abbot at Tiantong monastery when Zen Master Dogen visited China around 1225. Hongzhi once said, "Even if your measuring cup is full and the balance scale is level, in transactions I sell at a high price and buy when cheap. Zen worthies, do you understand? In a bowl, the bright pearl rolls on its own without prodding." Hongzhi also said, "For a luminous jewel without flaw, if you carve a pattern its virtue is lost."

Twenty years later, Dogen told his followers, "I, old man Daibutsu, do not agree. Great assembly, listen carefully and consider this well. For a luminous jewel without flaw, if polished its glow increases."

"For a luminous jewel without flaw, if you carve a pattern its virtue is lost" implies that Buddha-nature is perfect as it is - one can't improve it and shouldn't even try. Practice and enlightenment are one, but for Hongzhi, the emphasis was on enlightenment, with practice as its natural function, like the pearl rolling on its own. That is why in his first statement, he maintains that even if a merchant is scrupulously honest and thereby "perfect," the natural practice is to buy low and sell high. The full cup and the level balance are the perfect Buddha-nature; buying low and selling high are the practices that naturally arise.

Dogen's statement, "if polished, its glow increases," implies that even though Buddha nature is perfect as it is, our practice can clarify and extend its manifestation. For Dogen, practice and enlightenment were also one, but the emphasis was on practice, the direct expression of enlightenment that can actually deepen the experience.

It was around this same time that Dogen commented on the story of Nangaku, in order to show Baso the futility of practicing zazen to become a Buddha, began polishing a roof tile claiming to be making a mirror. Dogen noted that even though practice with a goal toward attainment of anything was itself a delusion, in fact, the Eternal Mirror of enlightenment does arise from the practice of polishing.