At Sāketa. Sāriputta said to Anuruddha:

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

“Reverend, 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—keen, aware, and mindful, rid of desire and aversion for the world. I meditate observing an aspect of feelings … mind … principles—keen, aware, and mindful, rid of desire and aversion 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 directly know the entire galaxy.”