Samaṇa sutta: Ascetics

“Mendicants, there are three duties of an ascetic. What three? Undertaking the training in the higher ethics, the higher mind, and the higher wisdom. These are the three duties of an ascetic.

So you should train like this: ‘We will have keen enthusiasm for undertaking the training in the higher ethics, the higher mind, and the higher wisdom.’ That’s how you should train.”