A monk in the time of Vaṭṭagāmaṇī-Abhaya. During the troubles caused by the brigand Brāhmanatissa, he travelled about in the company of Isidatta Thera, maintaining themselves on whatever they could find. One day a maiden made three balls of food, gave one to Isidatta, the second to Mahāsoṇa, and wished to give the third to Isidatta; but her hand turned, and the food fell into Mahāsoṇa’s bowl. Later, he lived with five hundred others in Maṇḍalārāma-vihāra. One day, while in Kālakagāma for alms, they were entertained by a pious devotee. The latter asked for Mahāsoṇa and showed him special honour, though Mahāsoṇa was only a junior monk. Some time after, Mahāsoṇa returned to the Mahāvihāra in Anurādhapura and received many gifts, which he distributed among the Saṅgha. VibhA.446 ff.