Hui Ko asked, "Could you please teach me the supreme Buddhist Dharma?"
The Master said, "You can't learn the Dharma from others."
Hui Ko said, "I have trying to search for Dharma myself, but in vain. My heart is unsettled. My mind is ill-at-ease. Master, please pacify my heart for me."
The Master replied, "Give me your heart and I'll try to calm it down for you."
After pondering for a long time, Hui Ko said, "I have been searching for my heart, but I cannot find it."
Bodhidharma said instantly, "Now, I have comforted your heart already."
Hui Ko was enlightened all of a sudden. It is impossible to show the heart as its existence is only an illusion. The whole process of the creation and cessation of the heart, or the mind, is also an illusion.
When we are void of the illusion, the 'heart' is not there at all. Without any attachment, the pure Buddha's nature is revealed. The mind is finally at ease.