Kappasahassa sutta: A Thousand Eons

At one time Venerable Anuruddha was staying near Sāvatthī in Jeta’s Grove, Anāthapiṇḍika’s monastery. Then several mendicants went up to Venerable Anuruddha, exchanged greetings with him … and said:

“What things has Venerable Anuruddha developed and cultivated to attain great direct knowledge?”

“Reverends, I attained great direct knowledge by developing and cultivating the four kinds of mindfulness meditation. What four? I meditate observing an aspect of the body … feelings … mind … principles—keen, aware, and mindful, rid of covetousness and displeasure for the world. I attained great direct knowledge by developing and cultivating these four kinds of mindfulness meditation.

And it’s because of developing and cultivating these four kinds of mindfulness meditation that I recollect a thousand eons.”