“One perception arose in me: ‘Cessation of becoming is Nibbāna.’ Another perception faded out in me: ‘Cessation of becoming is Nibbāna’. Just as, Your Reverence, from a fire of splinters, one flame arises and another flame fades out, even so in me one perception arose: ‘Cessation of becoming is Nibbāna’ and another perception faded out in me: ‘Cessation of becoming is Nibbāna’. Yet at the same time, Your Reverence, I consciously perceived.” —Sāriputta Sutta (AN 10.7)
Ñāṇananda’s explanation: The unique feature of this samādhi is its very fluxional character. In it there is no such fixity as to justify a statement that it depends on (nissāya) some object (ārammaṇā) as its support—hence the frustration of gods and men who seek out the basis of the Tathāgata’s consciousness. Normally, the jhānas are characterized by an element of fixity on which consciousness finds a footing or a steadying point (viññāṇaṭṭhiti). It is on this very fixity that the illusion of the ego thrives. In the above jhāna of the emancipated one, however, the ego has melted away in the fire of wisdom which sees the cosmic process of arising and cessation. Not only has the concept ‘I’ (papañca par excellence) undergone combustion, but it has also ignited the data of sensory experience in their entirety. Thus in this jhāna of the Arahant, the world of concepts melts away in the intuitional bonfire of universal impermanence.
My explanation: This enigmatic and paradoxical state is a huge breakthrough in the realization of Nibbāna. The mind that can hold both the arising or a percept or awareness, and its fading out or passing away as well, can never be disturbed by that percept or awareness. Thus deliverance from sense perception and discursive thought is not through volitional suppression of it; nor can it be through logical nullification of its significance. The counteraction or nullification of a percept or awareness is achieved by expanding the mind to hold both its arising and cessation. The mind that can simultaneously hold the arising and cessation of all its contents is forever undisturbed. Thus Nibbāna is not a static state: far from it. It is a dynamic balance of mind encompassing its contents, arising spontaneously by the activity of nature, and passing away through the action of time. This is actual tranquillity, beyond cessation of consciousness. Its practice leads to an extraordinary and poignant state of awareness, in which the world is seen as simultaneously arising and passing away; and yet, nothing is, or is happening, at all—for the net effect is zero.