Dutiyanibbānapaṭisaṁyutta sutta: About Extinguishment (2nd)

So I have heard. At one time the Buddha was staying near Sāvatthī in Jeta’s Grove, Anāthapiṇḍika’s monastery. Now at that time the Buddha was educating, encouraging, firing up, and inspiring the mendicants with a Dhamma talk about extinguishment. And those mendicants were paying attention, applying the mind, concentrating wholeheartedly, and actively listening.

Then, understanding this matter, on that occasion the Buddha expressed this heartfelt sentiment:

“It’s hard to see what they call the ‘uninclined’,
for the truth is not easy to see.
For one who has penetrated craving,
who knows and sees, there is nothing.”