[523] Bhikkhus, there are these three things that a farmer householder must do first. What three? Here, bhikkhus, a farmer householder first of all makes his field well-plowed and well-harrowed; having first made the field well-plowed and well-harrowed, he plants the seeds at the proper time; having planted the seeds at the proper time, he lets the water in and lets it out at the right occasion. These, bhikkhus, are the three things that a farmer householder must do first.
In the same way, bhikkhus, there are these three things that a bhikkhu must do first. What three? The undertaking of the training in higher morality (adhisīla-sikkhā), the undertaking of the training in higher mentality (adhicitta-sikkhā), and the undertaking of the training in higher wisdom (adhipaññā-sikkhā). These, bhikkhus, are the three things that a bhikkhu must do first.
Therefore, bhikkhus, you should train yourselves thus: "Keen shall be our zeal (chanda) for the undertaking of the training in higher morality; keen shall be our zeal for the undertaking of the training in higher mentality; keen shall be our zeal for the undertaking of the training in higher wisdom." Thus, bhikkhus, should you train yourselves.
English translation from the Pali (Siam Raṭṭha edition) — under review, not for citation.