Re the base of infinite space where one experiences a sense of the infinity of space.
Is that space as in outer space/the universe … or space as in space eg freedom, liberty ie give me some space… or is it meant just as an ‘area’… or perhaps even a vacuum; a precursor to emptiness perhaps?
We are currently in the sensual plane and experience …what we experience. The form (rupa) plane, minus the sensual overlay is experienced in the form (or fine-material as it is sometimes called) jhana. As we know the higher up the jhana ladder one ascends one’s experience becomes more refined. When all ‘fine-material’ perceptions fall away, what is remaining is the ‘formless’ or ‘immaterial’ attainments. It is said the absence of form is causal to/delimts ‘space’ (akasa). The idea is that it possible to experience in the jhanas briefly, what the experiences of beings in other planes are like. We have to return to our own plane however. So if someone were to experience pure void, without any matter at all, that would be ‘space’ (akasa) as far as I understand it. However the immaterial being doesn’t just experience void- it is boundless void. It’s like trying to experience the entire ocean, at the same time. It is endless void… but the experience is of course impermanent.
(by matter here I mean anything solid, liquid, gaseous or a flame- plasma)
When focusing on the void, the void is the biggest disturbance in the field of perception.
When the void falls away, consciousness is the biggest disturbance in the field of perception.
When consciousness falls away, nothingness is the biggest disturbance in the field of perception.
When nothingness falls away, barely perceiving or not perceiving is the biggest disturbance in the field of perception.
When this smidgen of perception also falls away, cessation of all perception, (nirodhasamapatti, nibbana) is the ultimate peace.
Then there is nothing beyond this peace.
I’d just like to add that it might be helpful to translate rupa at times as ‘appearance’ - then you are relieved of thinking in terms of ‘space’ and ‘objects’. When you close your eyes, and any inner appearance is gone it’s possible to experience an unlimited inner space.