[465] And what, bhikkhus, is more to be done? [You should train thus:] "We will be guarded as to the doors in the sense faculties (indriya). Having seen a form (rūpa) with the eye, we will not grasp at its signs (nimitta) nor grasp at its details (anubyañjana); since, for one dwelling with the eye faculty unrestrained, evil, unwholesome states of covetousness and grief (abhijjhā-domanassa) might flow in upon him, we will practise for its restraint; we will guard the eye faculty; we will undertake restraint with regard to the eye faculty. Having heard a sound with the ear … having smelt an odour with the nose … having tasted a flavour with the tongue … having touched a tangible with the body … having cognized a mental phenomenon (dhamma) with the mind, we will not grasp at its signs nor grasp at its details; since, for one dwelling with the mind faculty unrestrained, evil, unwholesome states of covetousness and grief might flow in upon him, we will practise for its restraint; we will guard the mind faculty; we will undertake restraint with regard to the mind faculty." Thus indeed, bhikkhus, should you train.
Now, bhikkhus, it may be that you think: "We are endowed with moral shame (hiri) and fear of wrongdoing (ottappa); our bodily conduct is purified, our verbal conduct is purified, our mental conduct is purified, our livelihood is purified, and we are guarded as to the doors in the sense faculties. This much is enough; this much has been done; the goal of the ascetic life (sāmaññattha) has been attained by us; there is nothing more for us to do"—and you might rest content with just that much. I inform you, bhikkhus; I declare to you, bhikkhus: let not the goal of the ascetic life decline for you who seek the goal of the ascetic life, while there is still more to be done.
English translation from the Pali (Siam Raṭṭha edition) — under review, not for citation.