He was the son of a brahmin of the vacchagotta. Having heard the Buddha teach, he entered the Order and dwelt in a village settlement in Kosala. He learnt the doctrine from the various monks who came there from time to time, but it was not until he learnt from Sāriputta that he was able to distinguish between Sutta, Vinaya, and Abhidhamma. He thus became versed in the Tipiṭaka even before the First Council (On this see Brethren, p.66. n.1). He practised meditation and soon attained Arahantship (Thag.v.65; ThagA.i.147 f). Later he became a teacher of the doctrine.
According to Dhammapāla (ThagA.i.149), the soubriquet Ukkhepakata was given to him because he was able to teach and recite passages from the Tipiṭaka “casting them in their proper setting, according as they belonged to each Piṭaka.” The title was meant to emphasise his eminent repertory of orally learnt doctrine.
He had been a householder in the time of Siddhattha Buddha and had helped a guild who built a hall for the Buddha by giving them a pillar for the building.