You should understand that in buddha-dharma, what is called the dharma gate of the vast total aspect of mind essence includes the whole vast dharma without separating essence and appearance and without speaking of arising and ceasing. [From life to death] and up to and including bodhi and nirvana, there is nothing that is not mind essence. Without exception, all the myriad phenomena in the entire universe are nothing other than this one mind, with everything included and interconnected. These various dharma gateways are all equally one mind. Saying there is no difference at all [between essence ans appearance] is exactly how buddhists understand mind essence.

The Wholehearted Way
Eihei Dogen’s Bendowa

Some key terms from the above quote:

• bodhi — Sanskrit word meaning enlightenment or awakening
• buddha-dharma — teaching of the Buddha; another name for Buddhism
• dharma gate — opens one’s heart to the truth of the dharma
• nirvana — state of bliss or peace; means “to extinguish,” such as extinguishing the flame of a candle, but it is not understood to mean annihilation, rather, it is thought of as passing into another kind of existence