The noble eightfold path has a clearly defined and very specific final goal (pariyosāna), a precise destination (parāyana). This goal is the elimination of passion, the elimination of aggression, and the elimination of delusion. The realization of this goal is variously called the “gnosis and vision of liberation” (vimuttiñāṇadassana), the “gnosis of elimination” (khayeñāṇa), and the “gnosis of nibbāna” (nibbāna ñāṇa).
The Asaṅkhata Saṃyutta of the Saṃyuttanikāya offers thirty-three epithets for this goal, almost all of which are either metaphors or evocative terms suggestive of the various facets of this goal. But each of these epithets is then explicitly and unequivocally defined as the elimination of passion, aggression, and delusion. SN 43 Asaṅkhata Saṃyutta (1-44 combined & abridged):
And what, monks, is the not-fabricated (asaṅkhata)? The elimination of passion, the elimination of aggression, the elimination of delusion: this is called the not-fabricated.
And what, monks, is the not-inclined (anata)? The elimination of passion, the elimination of aggression, the elimination of delusion: this is called the not-inclined.
And what, monks, is the outflowless (anāsava)...the truth (sacca)...the farther shore (pāra)...the subtle (nipuṇa)...the very hard to see (sududdasa)...the unaging (ajajjara)...the stable (dhuva)...the undisintegrating (apalokita)...the non-indicative (anidassana)...the unproliferated (nippapañca)...the peaceful (santa)...the death-free (amata)...the sublime (paṇīta)...the auspicious (siva)...the secure (khema)...the elimination of craving (taṇhākkhaya)...the wonderful (acchariya)...the amazing (abbhuta)...the calamity-free (anītika)...the dhamma free of calamity (anītikadhamma)... is the extinguishment (nibbāna)...is the unafflicted (abyāpajjha)... is dispassion (virāga)... is purity (suddhi)...is freedom (mutti)...the unadhesive (anālaya)...the island (dīpa)...the cave (leṇa)...is the shelter (tāṇa)... is the refuge (saraṇa)...the destination (parāyana)? The elimination of passion, the elimination of aggression, the elimination of delusion: this is called the destination.
Of course, the most commonly used of these epithets is nibbāna.
Beyond the attainment of this goal, early Pāḷi Buddhism has nothing to say. SN 48.42 Uṇṇābhabrāhmaṇa Sutta informs us as follows:
“But master Gotama, what is it that nibbāna takes recourse in?”
“You have gone beyond the range of questioning, brāhmaṇa. You were unable to grasp the limit of questioning. For, brāhmaṇa, the holy life is lived with nibbāna as its ground, nibbāna as its destination, nibbāna as its final goal.”
There are two reasons why the Buddha had nothing to say about any matters beyond the attainment of this goal. The first is that any view regarding the postmortem existence or non-existence of an awakened arahant is not conducive to actually attaining the goal. It “does not lead to disenchantment, dispassion, cessation, calmness, direct gnosis, full awakening, nibbāna.” It is considered a fetter of view (diṭṭhisaṃyojana). MN 72 Aggivacchagotta Sutta:
The view that after death a tathāgata exists is a thicket of views, a wilderness of views, a contortion of views, a vacillation of views, a fetter of views. It is accompanied by dissatisfaction, distress, despair, and fever. It does not lead to disenchantment, dispassion, cessation, calmness, direct gnosis, full awakening, nibbāna.
The view that after death a tathāgata does not exist is a thicket of views, a wilderness of views, a contortion of views, a vacillation of views, a fetter of views. It is accompanied by dissatisfaction, distress, despair, and fever. It does not lead to disenchantment, dispassion, cessation, calmness, direct gnosis, full awakening, nibbāna.
The view that after death a tathāgata both exists and does not exist is a thicket of views, a wilderness of views, a contortion of views, a vacillation of views, a fetter of views. It is accompanied by dissatisfaction, distress, despair, and fever. It does not lead to disenchantment, dispassion, cessation, calmness, direct gnosis, full awakening, nibbāna.
The view that after death a tathāgata neither exists nor does not exist is a thicket of views, a wilderness of views, a contortion of views, a vacillation of views, a fetter of views. It is accompanied by dissatisfaction, distress, despair, and fever. It does not lead to disenchantment, dispassion, cessation, calmness, direct gnosis, full awakening, nibbāna.
The other reason, as suggested by the Buddha’s exchange with the brāhmaṇa Uṇṇābha already mentioned, is that there is no way to describe or designate or define anything beyond the attainment of this goal.
The most elegant and subtle aspect of the dhamma expounded in the Nikāyas is that it doesn’t impose any sort of metaphysical view regarding the nature of the liberated mind. This is clear in the sense of the liberated, measureless mind → appamāṇacetasa, being free from any sort of measuring → pamāṇa.
It is precisely this which differentiates early Buddhism from every other religious and secular worldview. An arahant cannot be measured even while alive, and specifically, cannot be measured using the criteria of the aggregates. Since this is the case, there is nothing whatsoever that can be posited about the postmortem arahant. Language and logical inference don’t apply to that which cannot be qualified or measured. There is no criteria for measurement.
http://measurelessmind.ca/pariyosana.html