Sadhu, Bhante, thank you!
Well then, bhikku, purify the very starting point of wholesome states. And what is the starting point of wholesome states? Virtue that is well purified and view that is straight. Then, bhikku, when your virtue is well purified and your view straight, based upon virtue, established upon virtue, you should develop the four establishments of mindfulness in a threefold way.
-The Connected Discourses of the Buddha
by Bhikku Bodhi, page 1629
That's from Samyutta Nikaya 47.3. The context is a bhikku asking for the training in brief. The threefold way is the practice of the four foundations of mindfulness internally, externally, and internally & externally. The bhikku went on to become an arahant.