Mahānāmasutta
Ekaṁ samayaṁ bhagavā sakkesu viharati kapilavatthusmiṁ nigrodhārāme. Atha kho mahānāmo sakko yena bhagavā tenupasaṅkami; upasaṅkamitvā bhagavantaṁ abhivādetvā ekamantaṁ nisīdi. Ekamantaṁ nisinno kho mahānāmo sakko bhagavantaṁ etadavoca: “kittāvatā nu kho, bhante, upāsako hotī”ti? “Yato kho, mahānāma, buddhaṁ saraṇaṁ gato hoti, dhammaṁ saraṇaṁ gato hoti, saṅghaṁ saraṇaṁ gato hoti; ettāvatā kho, mahānāma, upāsako hotī”ti.
With Mahānāma
At one time the Buddha was staying in the land of the Sakyans, near Kapilavatthu in the Banyan Tree Monastery. Then Mahānāma the Sakyan went up to the Buddha, bowed, sat down to one side, and said to him: “Sir, how is a lay follower defined?” “Mahānāma, when you’ve gone for refuge to the Buddha, the teaching, and the Saṅgha, you’re considered to be a lay follower.”