דיגהה ניקאיה 1:1004
SUJATOYañca, ānanda, rattiṁ tathāgato anuttaraṁ sammāsambodhiṁ abhisambujjhati, yañca rattiṁ anupādisesāya nibbānadhātuyā parinibbāyati.
The night when a Realized One awakens to the supreme perfect awakening; and the night he becomes fully extinguished in the element of extinguishment with no residue.