Here's my translation of the last two paragraphs of Chapter Four of the Great Master Sixth Ancestor's Dharma Treasure Platform Sutra.
I recently attended a 7-day Zen retreat (sesshin) with the Pacific Zen Institute. The PZI "Old Teacher" (Roshi) John Tarrant is working with koans in a way that harkens back to the ancient Chinese open assembly presentations of koans. In the opening talk of retreat, he presented the koan "There is one treasure hidden in the body" as a theme for the retreat.
This section of Huineng's Platform Sutra arose in mind as an appropriate context for the inquiry of this koan:
"Learned and virtuous ones. A person who is without is without what? A thoughtful person thinks of what thing? A person who is without is without the characteristics of duality and without the various dusts and troubles of the heart-mind. A thoughtful person thinks of the original nature of True Suchness. True Suchness, as it is, is the essence of thought; thought, as it is, is the function of True Suchness. One's nature of True Suchness gives rise to thinking; neither the eye, ear, nose, or tongue is able to think. True Suchness is present as nature, therefore it can give rise to thinking. If one is without True Suchness, what is regarded as seeing and hearing, color and sound, as they are at that time are destroyed.
"Learned and virtuous ones. When one's nature of True Suchness gives rise to thinking, even if the six organs are present to see and hear, perceive and know, they are not contaminated by the 10,000 objective phenomena, and the true nature is always autonomous. For this reason the [Vimalakirti Nirdesa] Sutra says, 'Being able to properly differentiate the various characteristics of things is being at the primary meaning and immovable.'"
[T48n2008_p0353a28(03) to T48n2008_p0353b06(02)]
The English term "True Suchness" is the translation of the Chinese term 真如 which is the Chinese translation of the Sanskrit Bhūtatathatā. Other possible translations could be "Actual Thusness", "Real Suchness", "Genuine Thusness," etc.
The English term "characeristics of things" is the translation of the Chinese term 法相 which is the Chinese translation of the Sanskrit dharmalaksana.
I remembered this section of the Platform Sutra from several translations including Wong Moulam, Charles Luk, and Fung and Fung, and each of course has different nuances and interpretations of the text, so I've now done my own translation to zero in on this most important section. As I see it, this section is one of the core expressions of the variations on the central theme of Huineng's teaching.
This aspect of the teaching is pointing directly to how the Eight consciousnesses function. The Eighth Constiousness (Alayavijnana) is the essence of thought spoken of here by the name True Suchness. Awareness flows as the function of True Suchness and beoomes thinking. As thinking awareness flows into the senses the objectivity and appearance of a world is formed. In meditation, the function of the koan is to direct attention and awareness to "turn around" to the essence of thinking as it arises directly from True Suchness. This turning around is the paravritti referred to in the Lankavatara Sutra.
It should be understood that the term for "thinking," as a technical term, is inclusive of all mental formations including remembrance and thus memory. In this context D.T. Suzuki wrote in his Studies In the Lankavatara Sutra:
In short, the world starts from memory, memory in itself as retained in the Alaya universal is no evil, and when we are removed from the influence of false discrimination the whold Vijnana system woven around the Alaya as sentre experiences a revulsion toward true perception (paravritti). This is the gist of the teaching of the Lankavatara.(p. 184)
From this we should understand that Huineng's teaching about directing awareness to that which gives rise to thinking is exactly the teaching of Bodhidharma and the Lankavatara Sutra and not be under any delusions that Huineng did not accept the teachings of the Lankavatara and in some way preferred the Diamond Cutter Sutra.
Enjoy the Dharma.