"Good friends, my teaching of the Dharma takes meditation (ting) and wisdom (hi) as its basis. Never under any circumstances say mistakenly that meditation and wisdom are different; they are a unity, not two things. Meditation itself is the substance of wisdom; wisdom itself is the function of meditation. At the very moment when there is wisdom, then meditation exists in wisdom; at the very moment when there is meditation, then wisdom exists in meditation. Good friends, this means that meditation and wisdom are alike. Students, be careful not to say that meditation gives rise to wisdom, or that wisdom gives rise to meditation, or that meditation and wisdom are different from each other. To hold this view implies that things have duality-if good is spoken while the mind is not good, meditation and wisdom will not be alike. If mind and speech are both good, then the internal and the external are the same and meditation and wisdom are alike."
From The Platform Sutra of Hui-neng, the Sixth Patriarch of Chan Buddhism.