MN 1:74.1–74.5

nibbānaṁ nibbānato abhijānāti; nibbānaṁ nibbānato abhiññāya nibbānaṁ na maññati, nibbānasmiṁ na maññati, nibbānato na maññati, nibbānaṁ meti na maññati, nibbānaṁ nābhinandati. Taṁ kissa hetu? ‘Pariññātaṁ tassā’ti vadāmi. Khīṇāsavavasena tatiyanayabhūmiparicchedo niṭṭhito.

They directly know extinguishment as extinguishment. Having directly known extinguishment as extinguishment, they do not conceive it to be extinguishment, they do not conceive it in extinguishment, they do not conceive it as extinguishment, they do not conceive that ‘extinguishment is mine’, they do not approve extinguishment. Why is that? Because they have completely understood it, I say.