He was a fisherman's son and held the false view that, according to the Buddha's teaching, a man's consciousness runs on and continues without break of identity.
Sáti's colleagues did their best to change his way of thinking, but failing to do so, they reported the matter to the Buddha. He questioned Sáti, who, however, sat silent and glum; then the Buddha preached to him and the assembled monks the Mahátanhásankhaya Sutta (M.i.256 ff).
Buddhaghosa explains (MA.i.477) that Sáti was not a learned man. He knew only the Játakas, and his views were due to the fact that in the Játakas various characters were identified with the Buddha.