At Shūnyam, and only at Shūnyam, is there neither necessity nor urge to posit an artificial ‘Object’ to partner a now confirmed absent Subject. To convincingly and irreversibly arrive here is the only reliable marker of having alighted on Shūnyam.
If someone stops by your door and asks: ‘What is Truth?’, you pack him a sandwich, show him the ‘Backward Step’, and suggest that he watch-out for falling rocks and deceptively shallow puddles. Other than that, you don’t say a word.
If you must say a word, it may only be as Self-Eating Expression [try ‘That’]. And its limit is as the Symbol ‘0’.
‘Silence’ [Mounam] has a long history going back to the Māṇḍūkya Upaniṣad and the mystic Mantra AUM. The Sound ‘Silence!’ itself is the auditory analogue of Shūnyam. The late-stage teachings were Rahásya, ‘Secret’. [‘Mute’ as in ‘Silent’, is from the Sanskrit Mūka]
[But ‘Silence’ is also the ripest plum for mystical obscurantists and book-read teachers who have had a field-day with the word for centuries. They can mystify a brick but this one is a particularly rich lode.]
‘Neti! Neti!‘ shouted Yagnavalkya.
The Buddha famously held his Silence [Avyākṛta, Anirvacaniya] to all questions about the terminus.
Bodhidharma [circa 500 CE], the Founding Patriarch of C’han-Zen defines the ends of Practice:
‘A special transmission outside the scriptures; no dependence on words and letters; seeing into one’s self-nature and the attaining to Buddha-hood.’
Vimalakīrti, a man I would have related to, liked to spend his evenings at the cat-houses and casinos of the vibrant old city of Vaishali [now long dead, having been overrun by Religion].
Asked to ‘Explain the door to Non-Dual Understanding’, he stood silent. ‘Vimalakirti’s Lion’s Roar’ [Vimalakirt Sūtra].
From the Jǐngdé Records [Jǐngdé chuándēng], circa 10th Century CE:
Bodhidharma asked, “Can each of you say something to demonstrate your understanding?”
Dao Fu stepped forward and said, “It is not bound by words and phrases, nor is it separate from words and phrases. This is the function of the Tao.”
Bodhidharma: “You have attained my skin.”
The nun Zong Chi stepped up and said, “It is like a glorious glimpse of the realm of Akshobhya Buddha. Seen once, it need not be seen again.”
Bodhidharma; “You have attained my flesh.”
Dao Yu said, “The four elements are all empty. The five skandhas are without actual existence. Not a single dharma can be grasped.”
Bodhidharma: “You have attained my bones.”
Finally, Dazu Huike came forth, bowed deeply in silence and stood up straight.
Bodhidharma said, “You have attained my marrow.”
The Robe and Bowl were passed on to Dazu Huike.
The above are just some of the accessible examples available as I write this Post. Parallel terms exist in every serious literate tradition. If the mainstream orthodoxy has hidden them away, look in the Mystical School files.