Bhikkhusutta 1.9

1.9

Yato kho te, bhikkhu, sīlañca suvisuddhaṃ bhavissati diṭṭhi ca ujukā, tato tvaṃ, bhikkhu, sīlaṃ nissāya sīle patiṭṭhāya cattāro satipaṭṭhāne tividhena bhāveyyāsi.

When your ethics are well purified and your view is correct, you should develop the four kinds of mindfulness meditation in three ways, depending on and grounded on ethics.