The Transmission Gāthā of the Twenty-third Patriarch, the Great Being Hāriṇa

Original text:认得心性时，可说不思议；了了无可得，得时不说知。

Explanation: When, through practice, we see the mind and attain realization, recognizing our own fundamental mind and nature, we then know that this mind-nature is truly inconceivable. No matter how sentient beings use their discriminating consciousness and mind, their emotional understanding and deliberation (manasikāra), they cannot fathom Him; His essential nature is so subtle and difficult to know. Although we have recognized our own mind-nature, this mind-nature is also utterly unobtainable — He is our own inherent family treasure, an antique heirloom; when the conditions are complete, He is dug out, not obtained from outside, nor given by another. Even when we recognize Him, we cannot say that we have fully known all of His essential nature; we have only known the general characteristics. The rest of His deeper and subtler essential qualities must await the future path of cultivation, to be explored and uncovered bit by bit, until finally we attain omniscience (sarvākārajñatā) and perfect the Buddha way.