Digha Nikaya 1:1013
SUJATOAtha kho bhagavā mahatā bhikkhusaṅghena saddhiṁ yena kakudhā nadī tenupasaṅkami; upasaṅkamitvā kakudhaṁ nadiṁ ajjhogāhetvā nhatvā ca pivitvā ca paccuttaritvā yena ambavanaṁ tenupasaṅkami.
Then the Buddha together with a large Saṅgha of mendicants went to the Kakudhā River. He plunged into the river and bathed and drank. And when he had emerged, he went to the mango grove,