Searching for a sutta where Buddha talks about Nibbana

Question

I am searching for sutta where Buddha talks about Nibbana.

Also, there is one sutta where he says, "ah nothingness, great is this nothingness..." or something and his disciple replies, "What is so great where nothing happens".

Can anyone please help me find the sutta?

Answer 1

From AN 9.34:

Ven: Sariputta: “Reverends, extinguishment (Nibbana) is bliss!

Ven. Udayi: “But Reverend Sāriputta, what’s blissful about it, since nothing is felt?”

Ven. Sariputta: “The fact that nothing is felt is precisely what’s blissful about it.

Sukha or happiness for an unenlightened person is experienced when encountering pleasant feelings (from the six senses, including thoughts and the intellect) or when encountering the cessation of painful feelings (from the six senses).

But for a Buddha or arahat, sukha or bliss (in this context) is experienced when encountering neutral feelings, no feelings and Nibbana.

Please see this answer for commentaries by Nyanaponika Thera. The supporting suttas are MN 44, SN 36.5 and AN 9.34.

From Ud 8.1:

Then, on realizing the significance of that, the Blessed One on that occasion exclaimed:

There is that dimension, monks, where there is neither earth, nor water, nor fire, nor wind; neither dimension of the infinitude of space, nor dimension of the infinitude of consciousness, nor dimension of nothingness, nor dimension of neither perception nor non-perception; neither this world, nor the next world, nor sun, nor moon. And there, I say, there is neither coming, nor going, nor staying; neither passing away nor arising: unestablished, unevolving, without support [mental object]. This, just this, is the end of stress (suffering).

From Ud 8.3:

Then, on realizing the significance of that, the Blessed One on that occasion exclaimed:

There is, monks, an unborn — unbecome — unmade — unfabricated. If there were not that unborn — unbecome — unmade — unfabricated, there would not be the case that escape from the born — become — made — fabricated would be discerned. But precisely because there is an unborn — unbecome — unmade — unfabricated, escape from the born — become — made — fabricated is discerned.