Ayācana Suttaṁ: The Discourse on Brahma’s Request
This is how I heard. At one time the Blessed One was staying in the province of Uruvelā on the Nerañjarā river bank at the foot of the Goatherd’s Banyan tree, just after the Blessed One had become fully enlightened. Then, while the Blessed One was alone in meditation, a thought occurred in his mind thus:
“This Dhamma that I have realized is deep, hard to see, hard to understand, peaceful and sublime, cannot be realized by reasoning, subtle, and to be experienced by the wise. But this generation is stuck in desire, delights in desire, and rejoices in desire. For a generation that is stuck in desire, delights in desire, and rejoices in desire, realizing this Dhamma that is about the law of causality and the law of dependent arising will be very hard to understand. Nibbāna is the state of dispassion, cessation, stilling in all formations, eradication of all defilements, and the destruction of craving. Attaining this Nibbāna is very hard for such a generation.
“Therefore if I were to teach the Dhamma and if others would not understand me, that would be tiresome for me, and that would be troublesome for me.”