MN 1:26.1–26.5

Nibbānaṁ nibbānato sañjānāti; nibbānaṁ nibbānato saññatvā nibbānaṁ maññati, nibbānasmiṁ maññati, nibbānato maññati, nibbānaṁ meti maññati, nibbānaṁ abhinandati. Taṁ kissa hetu? ‘Apariññātaṁ tassā’ti vadāmi. Puthujjanavasena paṭhamanayabhūmiparicchedo niṭṭhito.

They perceive extinguishment as extinguishment. Having perceived extinguishment as extinguishment, they conceive it to be extinguishment, they conceive it in extinguishment, they conceive it as extinguishment, they conceive that ‘extinguishment is mine’, they approve extinguishment. Why is that? Because they haven’t completely understood it, I say.