For another take on the same topic, this is from Bhikkhu Nanananda's "Nibbana and the Fire Simile"
. I suggest reading the whole article to get the whole context of this passage, but the most relevant bit is:
There is a particular term in the Dhamma to indicate the consciousness which lacks germinating power – namely 'Anidassana viññāõa' – non-manifestative consciousness. There is nothing in that consciousness that can manifest itself or show up. This is the state that the Buddha made known to the world as an extraordinary sphere (āyatana). The world is familiar with only the six sense spheres – eye, ear, nose, tongue, body and mind. They become spheres when they are involved in activity with their respective sense objects. That activity is similar to what is going on in the whirlpool mentioned above. According to the Buddha it is in these six sense spheres where this activity is going on, that the whole world is to be found. Whatever modern science may say, the Buddha has proclaimed that the world is something that arises and ceases in the six sense spheres. That is why the Buddha declared that within this fathom-long physical frame with its perception and mind he would point out the world, the arising of the world, the cessation of the world and the path leading to the cessation of
Sometimes the Buddha preached about a state wherein the six sense spheres cease. That cessation of sense spheres itself is called a sphere – a sphere one can realize. He even gives a description of it. “Monks, there is that sphere” – what sort of sphere ? In that sphere the Buddha has described, there is
nothing of those elements like earth, water, fire and air with which we associate matter or form, none of the formless realms like the realm of infinity of space, no this world, no other world, no sun, no moon, no coming, no going, no standing, no passing away, no being born. In short, as the Buddha sums it up, that state is unestablished (appatiññha§), non-continuing (appavatta§) and objectless (anārammana§). The long list of negations is suggestive of the absence of all Sa§sāric bonds – everything that mattered including 'matter' itself. It is this non-manifestative consciousness that the arahants experience in the attainment of the Fruit of Arahanthood.
Disciples, this I declare to you: All conditioned things are subject to disintegration – strive on untiringly for your liberation.
Sotthī hontu nirantaraṃ - May you forever be well.