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

Silāyūpa sutta - Stone Pillar

Discourse on the Stone Pillar

At one time, the venerable Sāriputta and the venerable Candikāputta were dwelling in Rājagaha, in the Bamboo Grove, the Squirrels' feeding ground.

There the venerable Candikāputta addressed the bhikkhus: "Friends, Devadatta teaches the bhikkhus thus: 'When, friends, a bhikkhu's mind is composed, it is proper for that bhikkhu to declare: "Birth is ended, the spiritual life has been lived, what had to be done has been done, there is no more coming to any state of being."'"

Having said this, the venerable Sāriputta addressed the venerable Candikāputta: "Friend, Candikāputta, Devadatta does not teach the bhikkhus thus: 'When, friends, a bhikkhu's mind is composed, it is proper for that bhikkhu to declare: "Birth is ended, the spiritual life has been lived, what had to be done has been done, there is no more coming to any state of being."' But rather, friend, Candikāputta, Devadatta teaches the bhikkhus thus: 'When, friends, a bhikkhu's mind is well-composed, it is proper for that bhikkhu to declare: "Birth is ended, the spiritual life has been lived, what had to be done has been done, there is no more coming to any state of being."'"

For a second time, the venerable Candikāputta addressed the bhikkhus: "Friends, Devadatta teaches the bhikkhus thus: 'When, friends, a bhikkhu's mind is composed, it is proper for that bhikkhu to declare: "Birth is ended, the spiritual life has been lived, what had to be done has been done, there is no more coming to any state of being."'" For a second time, the venerable Sāriputta addressed the venerable Candikāputta: "Friend, Candikāputta, Devadatta does not teach the bhikkhus thus: 'When, friends, a bhikkhu's mind is composed, it is proper for that bhikkhu to declare: "Birth is ended, the spiritual life has been lived, what had to be done has been done, there is no more coming to any state of being."' But rather, friend, Candikāputta, Devadatta teaches the bhikkhus thus: 'When, friends, a bhikkhu's mind is well-composed, it is proper for that bhikkhu to declare: "Birth is ended, the spiritual life has been lived, what had to be done has been done, there is no more coming to any state of being."'"

For a third time, the venerable Candikāputta addressed the bhikkhus: "Friends, Devadatta teaches the bhikkhus thus: 'When, friends, a bhikkhu's mind is composed, it is proper for that bhikkhu to declare: "Birth is ended, the spiritual life has been lived, what had to be done has been done, there is no more coming to any state of being."'"

For a third time, the venerable Sāriputta addressed the venerable Candikāputta: "Friend, Candikāputta, Devadatta does not teach the bhikkhus thus: 'When, friends, a bhikkhu's mind is composed, it is proper for that bhikkhu to declare: "Birth is ended, the spiritual life has been lived, what had to be done has been done, there is no more coming to any state of being."' But rather, friend, Candikāputta, Devadatta teaches the bhikkhus thus: 'When, friends, a bhikkhu's mind is well-composed, it is proper for that bhikkhu to declare: "Birth is ended, the spiritual life has been lived, what had to be done has been done, there is no more coming to any state of being."'

And how, friend, is a bhikkhu's mind well-composed? My mind is free from passion,' thus the mind is well-composed; 'My mind is free from aversion,' thus the mind is well-composed; 'My mind is free from delusion,' thus the mind is well-composed; 'My mind is free from the tendencies of passion,' thus the mind is well-composed; 'My mind is free from the tendencies of aversion,' thus the mind is well-composed; 'My mind is free from the tendencies of delusion,' thus the mind is well-composed; 'My mind is not turning towards the sense realm,' thus the mind is well-composed; 'My mind is not turning towards the form realm,' thus the mind is well-composed; 'My mind is not turning towards the formless realm,' thus the mind is well-composed.

Thus, friend, when a bhikkhu's mind is rightly released, even if many forms cognizable by the eye come into the range of the eye, they do not obsess the mind; the mind remains untainted, steady, and attained to imperturbability, and he observes their passing away.

Just as, friend, a stone pillar sixteen spans deep stands firm. It has eight parts below well-fixed, and eight parts above. If strong wind and rain were to come from the east, it would neither shake nor tremble; if strong wind and rain were to come from the west, from the north, from the south, it would neither shake nor tremble. And why is that? Because of the depth and the well-planted nature of the stone pillar. So too, friend, when a bhikkhu's mind is rightly released, even if many forms cognizable by the eye come into the range of the eye, they do not obsess the mind; the mind remains untainted, steady, and attained to imperturbability, and he observes their passing away.

Even if many sounds cognizable by the ear, odors cognizable by the nose, tastes cognizable by the tongue, tactile objects cognizable by the body, or mental objects cognizable by the mind come into the range of the mind, they do not obsess the mind; the mind remains untainted, steady, and attained to imperturbability, and he observes their passing away."