on what the Buddha taught
Idha, bhikkhave, bhikkhu kāye kāyānupassī viharati ātāpī sampajāno satimā vineyya loke abhijjhādomanassaṃ.
'Here, almsmen, an almsman looking at the body, dwells in the body; as the ardent aware recollector would remove the avarice and distress about the world.' (AN4.274)
If you watch television, you can dwell in it. If you look at the past, you can dwell in it. But not while you keep track of the surroundings. So in order to dwell in them the surrounding will have to make room first. And how it this done? By loosing interest in it.
Like that; with the removal of the avarice and distress, all interests and concerns about the world are gone and the world disappears for one. What remains to dwell in is the body, that is if what is looked at is the body; or feelings if what is looked at are feelings. And so does this text not differ much from other texts like Concise on Emptiness; with the perception of the world gone, the remaining non-emptiness is the perception of body. With the perception of body gone, the remaining non-emptiness is the perception of feelings ... mind ... principles. It is the same method of emptying, stepping back, gradual stilling, disenchantment.