He was the son of a banker in Setabyā and he went to see the Buddha who was visiting the town and staying in the Siṃsapāvana. The Buddha taught him on the impermanence of all component things and at the end of the discourse he became an Arahant. He received his name because he won insight by hearing the Dhamma only once.

In the time of Padumuttara Buddha he was a tree-sprite and, coming across some monks who had lost their way, he looked after them, gave them food and directed them to their destination. After the death of Kassapa Buddha, he was born as the son of Suyāma and great-grandson of Kikī and became king of Bārāṇasī under the name of Kikī Brahmadatta. Not finding anyone capable of teaching the Doctrine to him, he left his throne in disgust and started on his way to Himavā. As he went along the road, Sakka appeared before him and quoted to him some lines on the impermanence of all things. Satisfied therewith, the king returned to his capital (Thag.v.67; ThagA.i.151 f).

The Apadāna verses regarding this Thera quoted in the Theragāthā Commentary are, in the Apadāna itself (i.152 f), attributed to an elder named Maggasaññaka, with whom he is evidently to be identified. Five world-cycles ago he became king twelve times under the name of Sacakkhu.