He was the son of Samiddhi, a brahmin of Nálaka in Magadha. Mahágavaccha admired Sáriputta greatly, and on learning that he had joined the Order, he followed Sáriputta's example, becoming an arahant in due course.
In the past he gave a drink of water to Padumuttara Buddha and was a devout follower of Sikhí Buddha (Thag.vs.12; ThagA.i.57). He is probably identical with Udakadáyaka of the Apadána. Ap.ii.437; but the same verses are attributed to Gangátiriya (ThagA.i.249).