He was the son of a very rich setthi of Benares. When he came of age, his parents married him and he had a son. One day he joined a party of people going to Jetavana, and, at the conclusion of the Buddha's sermon, asked the Buddha to ordain him. But the Buddha wished him to have his parent's leave. This he obtained only with the greatest difficulty and with the promise to visit them later. After ordination he lived in a forest grove, and soon afterwards attained arahantship.
When he returned to Sávatthi, after having paid homage to the Buddha, he spent the noonday under a tree. His parents, hearing of his arrival, went to see him. Their efforts to persuade him to return to lay life were too insistent, and he would not even speak to them. They returned discomfited and sent his wife and son to him. His wife appealed to him with various arguments, but he refused even to look at her. She then placed the child on his lap and went away. When she discovered that Sangámaji would not even talk to his son, she took him away, saying that her husband was a useless man.
The Buddha saw all this with his divine eye and expressed his joy in verse. Ud.i.8; UdA.71ff.; the verse is quoted at Netti, p.150.
Posiya Thera was Sangámaji's younger brother. ThagA.i.97.