Mahā-Moggallāna wonders how many devas have become Stream-winners and are assured of nibbāna. In order to discover this, he visits Tissa Brahmā, who had once been a monk. Tissa welcomes him and tells him that only those devas who have faith in the Buddha, the Dhamma, and the Saṅgha have such assurance. A.iii.331 f.