Called Kākandakaputta. He was the son of the brahmin Kākandaka and was a pupil of Ānanda. It is said he was fortunate enough to see the Buddha alive (Mhv.iv.57 f).

When he arrived at the Kūṭāgārasālā in the Mahāvana, he discovered that the Vajjī monks had raised the “Ten Points” (dasavatthu) contrary to the Buddha’s teachings, and that they were publicly asking for money from their lay disciples. Yasa thereupon protested against such misdemeanours, and the Vajjī monks, hoping to win him over, offered him a share of the money they had collected.

This offer he rejected with scorn, and the monks passed on him the Paṭisāraṇīya kamma (obliging him to seek pardon from the laity). This necessitated that Yasa should be sent among the laymen, accompanied by a messenger, presumably to ask their pardon for having misinformed them. However, instead of this, Yasa told the lay people that the behaviour of the Vajjī monks was completely at variance with the rules laid down by the Buddha, and quoted the Buddha’s discourses to prove his charge.

When the Vajjī monks heard of this, they pronounced on him a formal Act of Suspension (Ukkhepanīya Kamma), but when they assembled to carry it out, Yasa disappeared through the air to Kosambī, from where he sent messengers to the monks of Avanti, of the west (Pātheyyakā or Pāveyyakā) and of the south (Dakkhiṇāpatha), asking for their assistance in checking the corruption of the religion. With them he visited Sambhūta-Sānavāsi at Ahogaṅga-pabbata, and there they decided to consult Revata who lived in Soreyya. Yasa, therefore, went to Revata, following him through Saṅkassa, Kaṇṇakujja, Udumbara, Aggalapura and Sahajāti. Having found Revata, he questioned him regarding the ten points, and obtained from him promise of assistance.

Together they returned to Vesāli, where lived Sabbakāmī, the oldest Thera of the day. After obtaining his opinion on the matter, an assembly of the monks was held and a committee was appointed — to settle the matter by a referendum (ubbāhikā) — of four from the East: Sabbakāmī, Sāḷha, Khujjasobhita, and Vāsabhagāmika; and four from the West: Revata, Sambhūta-Sānavāsi, Yasa, and Sumana. They debated the question at the Vālikārāma, Revata acting as questioner and Sabbakāmī answering his questions. At the end of the enquiry the decision was given against the ten points of the Vajjī monks, and this decision was conveyed to the assembly. Then the recital of the Vinaya was held in which seven hundred monks participated; this recital was called the Sattasatī. Vin.ii.294 ff; Mhv.iv.9 ff;; Dpv.iv.45 ff; v.23. The Mhv. says that at first the king (Kāḷāsoka) was inclined to support the Vajjī, but his sister, Nandā Therī, warned him against this (iv. 37 ff.).

The monks who refused to accept the findings of the committee held another convocation, which was called the Mahāsaṅgīti (Dpv.v.30 ff.). The Sattasatī Recital (also called The Second Recital) was also named (e.g., AA.i.251; MA.ii.880) Yasathera Saṅgīti, evidently because of the prominent part played by Yasa.

Yasa is ranked (See, e.g., DA.ii.525) among the great benefactors of the religion.