To perceive an object in the space of awareness is sati. The mind aware of itself as that space is the deathless. But we do not stay in the space of mindfulness. We give the first space for the second of samādhi; this mind at one with the object is samādhi.
We close the space until there is no gap between seer and seen. Then, in the seeing of insight we see the space inside things. Seeing with insight is then like a light touch that generates this space. We see right there at the object. So this is a letting go of self, of the watcher until there is just the seen.
The deathless is a space that emerges out of things, not a space in which they are held - a space created by the object rather than an object by the space. It is a light shining out of things, a mind naturally created by things rather than things being created by the mind. Nibbāna is abiding in this particular space even in the absence of things.
It can be counter intuitive to go looking for Nibbāna in things if we see Nibbāna as getting away from things. But the only way out is in and through things.
Space emerging from the object is a sign of wisdom. The space of wisdom independent of the object is Nibbāna.
I offer this for your reflection