“Bhikkhus, if in any bhikkhu or bhikkhunī desire or lust or hatred or delusion or aversion of mind should arise in regard to forms cognizable by the eye, such a one should rein in the mind from them thus: ‘This path is fearful, dangerous, strewn with thorns, covered by jungle, a deviant path, an evil path, a way beset by scarcity. This is a path followed by inferior people; it is not the path followed by superior people. This is not for you.’ In this way the mind should be reined in from these states regarding forms cognizable by the eye. So too regarding sounds cognizable by the ear … regarding mental phenomena cognizable by the mind.
“Suppose, bhikkhus, that the barley has ripened and the watchman is negligent. If a bull fond of barley enters the barley field, he might indulge himself as much as he likes. So too, bhikkhus, the uninstructed worldling who does not exercise restraint over the six bases for contact indulges himself as much as he likes in the five cords of sensual pleasure.
“Suppose, bhikkhus, that the barley has ripened and the watchman is vigilant. If a bull fond of barley enters the barley field, the watchman would catch hold of him firmly by the muzzle. While holding him firmly by the muzzle, he would get a secure grip on the locks between his horns and, keeping him in check there, would give him a sound beating with his staff. After giving him that beating, he would drive the bull away. This might happen a second time and a third time. Thus that bull fond of barley, whether he has gone to the village or the forest, whether he is accustomed to standing or to sitting, remembering the previous beating he got from the staff, would not enter that barley field again.
“So too, bhikkhus, when a bhikkhu’s mind has been subdued, well subdued, regarding the six bases for contact, it then becomes inwardly steady, settled, unified, and concentrated.
“Suppose, bhikkhus, there was a king or a royal minister who had never before heard the sound of a lute. He might hear the sound of a lute and say: ‘Good man, what is making this sound—so tantalizing, so lovely, so intoxicating, so entrancing, so enthralling?’ They would say to him: ‘Sire, it is a lute that is making this sound—so tantalizing, so lovely, so intoxicating, so entrancing, so enthralling.’ He would reply: ‘Go, man, bring me that lute.’
“They would bring him the lute and tell him: ‘Sire, this is that lute, the sound of which was so tantalizing, so lovely, so intoxicating, so entrancing, so enthralling.’ The king would say: ‘I’ve had enough with this lute, man. Bring me just that sound.’ The men would reply: ‘This lute, sire, consists of numerous components, of a great many components, and it gives off a sound when it is played upon with its numerous components; that is, in dependence on the parchment sounding board, the belly, the arm, the head, the strings, the plectrum, and the appropriate effort of the musician. So it is, sire, that this lute consisting of numerous components, of a great many components, gives off a sound when it is played upon with its numerous components.’
“The king would split the lute into ten or a hundred pieces, then he would reduce these to splinters. Having reduced them to splinters, he would burn them in a fire and reduce them to ashes, and he would winnow the ashes in a strong wind or let them be carried away by the swift current of a river. Then he would say: ‘A poor thing, indeed sir, is this so-called lute, as well as anything else called a lute. How the multitude are utterly heedless about it, utterly taken in by it!’
“So too, bhikkhus, a bhikkhu investigates form to the extent that there is a range for form, he investigates feeling to the extent that there is a range for feeling, he investigates perception to the extent that there is a range for perception, he investigates volitional formations to the extent that there is a range for volitional formations, he investigates consciousness to the extent that there is a range for consciousness. As he investigates form to the extent that there is a range for form … consciousness to the extent that there is a range for consciousness, whatever notions of ‘I’ or ‘mine’ or ‘I am’ had occurred to him before no longer occur to him.”
Read this translation of Saṁyutta Nikāya 35.246 Vīṇopamasutta: The Simile of the Lute by Bhikkhu Bodhi on SuttaCentral.net.