Consciousness, while persisting, might persist attached to form, feeling, perception, and intentional constructs. When passion for these is abandoned, the support for the establishment of consciousness is completely cut off. That consciousness, being unestablished, does not grow, and by not intentionally constructing, is liberated.

By being liberated, there is stability; being stable, there is contentment; being content, there is |no perturbation::no agitation, no mental uneasiness [aparitassa]|. Unperturbed, one personally attains final Nibbāna.

Verses depicting the path to liberation through the central metaphor of a serpent shedding its skin. Each stanza illustrates how a bhikkhu abandons defilements like anger, passion, craving, and conceit, thereby casting off attachment to this world and the next.

One within whom no |perturbation::agitation, disturbance [kopa]| remains, who has left behind notions of |being and non-being::such success and failure, gain and loss, eternity and annihilation, good and evil [bhava + abhava]|; That bhikkhu abandons this world and the next, like a serpent casting off its old worn-out skin.

The venerable Udāyī asks the venerable Ānanda about how to see the not-self nature of consciousness.

Likewise, friend, a bhikkhu does not regard the six sense bases as self or as belonging to a self. With such perception, he does not cling to anything in the world. Without clinging, he is not perturbed. Without perturbation, he personally attains |Nibbāna::complete cooling, letting go of everything, deathless, freedom from calamity, the non-disintegrating [nibbāna]|.

The Buddha explains how even small attachments can be strong fetters if not relinquished, using similes of a quail and an elephant, and contrasts between the poor and wealthy. He describes four types of practitioners based on their response to attachment and mindfulness. The discourse also presents gradual refinement of meditative attainments from the first jhāna to the cessation of perception and feeling.

1) Here, Udāyī, a bhikkhu, having secluded himself from sensual pleasures and unwholesome mental qualities, enters and dwells in the first jhāna, which is accompanied by reflection and examination, born of seclusion, and filled with joyful pleasure. Now this, Udāyī, I say still involves |perturbation::agitation, disturbance, movement, turmoil [iñjita]|. And what, therein, is perturbation? Whatever reflection and examination has not yet ceased, this, therein, is perturbation.

Venerable Sāriputta clarifies on a teaching on how liberation is to be verified. He shares a simile of the stone pillar.

Discourse on the Stone Pillar