Because of GraspingUpādāyasutta

“Mendicants, when what exists, because of grasping what, do pleasure and pain arise in oneself?”“Kismiṁ nu kho, bhikkhave, sati kiṁ upādāya uppajjati ajjhattaṁ sukhaṁ dukkhan”ti?

“Our teachings are rooted in the Buddha. …”“Bhagavaṁmūlakā no, bhante, dhammā …pe….

“Mendicants, when there’s an eye, because of grasping the eye, pleasure and pain arise in oneself. …“Cakkhusmiṁ kho, bhikkhave, sati cakkhuṁ upādāya uppajjati ajjhattaṁ sukhaṁ dukkhaṁ …pe… When there’s a mind, because of grasping the mind, pleasure and pain arise in oneself.manasmiṁ sati manaṁ upādāya uppajjati ajjhattaṁ sukhaṁ dukkhaṁ.

What do you think, mendicants?Taṁ kiṁ maññatha, bhikkhave, Is the eye permanent or impermanent?”cakkhu niccaṁ vā aniccaṁ vā”ti?

“Impermanent, sir.”“Aniccaṁ, bhante”.

“But if it’s impermanent, is it suffering or happiness?”“Yaṁ panāniccaṁ dukkhaṁ vā taṁ sukhaṁ vā”ti?

“Suffering, sir.”“Dukkhaṁ, bhante”.

“But by not grasping what’s impermanent, suffering, and perishable, would pleasure and pain arise in oneself?”“Yaṁ panāniccaṁ dukkhaṁ vipariṇāmadhammaṁ, api nu taṁ anupādāya uppajjeyya ajjhattaṁ sukhaṁ dukkhan”ti?

“No, sir.” …“No hetaṁ, bhante” …pe….

“Is the ear … nose … tongue … body …“Jivhā niccā vā aniccā vā”ti? mind permanent or impermanent?”“Mano nicco vā anicco vā”ti?

“Impermanent, sir.”“Anicco, bhante”.

“But if it’s impermanent, is it suffering or happiness?”“Yaṁ panāniccaṁ dukkhaṁ vā taṁ sukhaṁ vā”ti?

“Suffering, sir.”“Dukkhaṁ, bhante”.

“But by not grasping what’s impermanent, suffering, and perishable, would pleasure and pain arise in oneself?”“Yaṁ panāniccaṁ dukkhaṁ vipariṇāmadhammaṁ, api nu taṁ anupādāya uppajjeyya ajjhattaṁ sukhaṁ dukkhan”ti?

“No, sir.”“No hetaṁ, bhante”.

“Seeing this, a learned noble disciple grows disillusioned with the eye, ear, nose, tongue, body, and mind.“Evaṁ passaṁ, bhikkhave, sutavā ariyasāvako cakkhusmimpi nibbindati …pe… manasmimpi nibbindati. Being disillusioned, desire fades away. When desire fades away they’re freed. When they’re freed, they know they’re freed.Nibbindaṁ virajjati; virāgā vimuccati; vimuttasmiṁ vimuttamiti ñāṇaṁ hoti.

They understand: ‘Rebirth is ended, the spiritual journey has been completed, what had to be done has been done, there is nothing further for this place.’”‘Khīṇā jāti, vusitaṁ brahmacariyaṁ, kataṁ karaṇīyaṁ, nāparaṁ itthattāyā’ti pajānātī”ti.