Gāvīupamāsutta
“Seyyathāpi, bhikkhave, gāvī pabbateyyā bālā abyattā akhettaññū akusalā visame pabbate carituṁ. Tassā evamassa: ‘yannūnāhaṁ agatapubbañceva disaṁ gaccheyyaṁ, akhāditapubbāni ca tiṇāni khādeyyaṁ, apītapubbāni ca pānīyāni piveyyan’ti. Sā purimaṁ pādaṁ na suppatiṭṭhitaṁ patiṭṭhāpetvā pacchimaṁ pādaṁ uddhareyya. Sā na ceva agatapubbaṁ disaṁ gaccheyya, na ca akhāditapubbāni tiṇāni khādeyya, na ca apītapubbāni pānīyāni piveyya; yasmiṁ cassā padese ṭhitāya evamassa: ‘yannūnāhaṁ agatapubbañceva disaṁ gaccheyyaṁ, akhāditapubbāni ca tiṇāni khādeyyaṁ, apītapubbāni ca pānīyāni piveyyan’ti tañca padesaṁ na sotthinā paccāgaccheyya. Taṁ kissa hetu? Tathā hi sā, bhikkhave, gāvī pabbateyyā bālā abyattā akhettaññū akusalā visame pabbate carituṁ. Evamevaṁ kho, bhikkhave, idhekacco bhikkhu bālo abyatto akhettaññū akusalo vivicceva kāmehi vivicca akusalehi dhammehi savitakkaṁ savicāraṁ vivekajaṁ pītisukhaṁ paṭhamaṁ jhānaṁ upasampajja viharati; so taṁ nimittaṁ na āsevati na bhāveti na bahulīkaroti na svādhiṭṭhitaṁ adhiṭṭhāti.
The Simile of the Cow
“Mendicants, suppose there was a mountain cow who was foolish, incompetent, unskillful, and lacked common sense when roaming on rugged mountains. She might think, ‘Why don’t I go somewhere I’ve never been before? I could eat grass and drink water that I’ve never tried before.’ She’d take a step with a fore-hoof; but before it was properly set down, she’d lift up a hind-hoof. She wouldn’t go somewhere she’d never been before, or eat grass and drink water that she’d never tried before. And she’d never return safely to the place she had started from. Why is that? Because that mountain cow was foolish, incompetent, unskillful, and lacked common sense when roaming on rugged mountains. In the same way, some foolish, incompetent, unskillful mendicant, lacking common sense, quite secluded from sensual pleasures, secluded from unskillful qualities, enters and remains in the first absorption, which has the rapture and bliss born of seclusion, while placing the mind and keeping it connected. But they don’t cultivate, develop, and make much of that basis; they don’t ensure it is properly stabilized.