Also called Paṇḍita Udāyī to distinguish him from Lāḷudāyī.

He was the son of a brahmin of Kapilavatthu. He saw the power and majesty of the Buddha when the latter visited his kinsmen and, entering the Order, in due course became an Arahant. When the Buddha taught the Nāgopama Sutta (see A.iii.344 f), on the occasion when Seta, King Pasenadi’s elephant, was publicly admired, Udāyī was stirred to enthusiasm by thoughts of the Buddha and uttered sixteen verses, extolling the virtues of the Buddha, comparing him to a great and wondrous elephant. (Thag.vv.689-704; ThagA.ii.7 f; Udāyī’s verses are repeated in the Aṅguttaranikāya (A.iii.346-7) but the Commentary (AA.ii.669) attributes them to Kāludāyī).

Once when Udāyī was staying at Kāmandā, in Todeyya’s mango-grove, he converted a pupil of a brahmin of the Verahaccāni clan and, as a result, was invited by Verahaccāni herself to her house. It was only on his third visit to Verahaccāni that Udāyī taught her and she thereupon became a follower of the Faith (S.iv.121-4).

The Saṃyuttanikāya (S.iv.166 f; another discussion with Ānanda is mentioned in A.iv.426 f) also records a conversation between Udāyī and Ānanda, when Udāyī asks if it is possible to describe the consciousness, too, as being without the self. On another occasion Udāyī has a discussion with Pañcakaṅga on feelings (vedanā) (M.i.396 ff; S.iv.223-4; the Commentary SA.iii.86 and MA.ii.629 here describes Udāyī as “Paṇḍita”). Ānanda overhears their conversation and reports it to the Buddha, who says that Udāyī’s explanation is true, though not accepted by Pañcakaṅga.

Elsewhere (S.v.86 ff) Udāyī is mentioned as asking the Buddha to instruct him on the factors of enlightenment (bojjhaṅga), and once, at Setaka in the Sumbha country, he tells the Buddha how he cultivated the factors of enlightenment and thereby attained final emancipation (S.v.89).

He is rebuked by the Buddha for his sarcastic remark to Ānanda, that Ānanda had failed to benefit by his close association with the Master. The Buddha assures him that Ānanda will, in that very life, become an Arahant (A.i.228).

Udāyī was evidently a clever and attractive teacher, for he is mentioned as having addressed large crowds, a task demanding great skill, as the Buddha himself says when this news of Udāyī is reported to him (A.iii.184).

According to Buddhaghosa (DA.iii.903), it is this same Udāyī (Mahā Udāyī) who, having listened to the Sampasādanīya Sutta, is beside himself with joy at the contemplation of the wonderful qualities as set forth in that Sutta, and marvels that the Buddha does not go about proclaiming them. Buddhaghosa (MA.i.526) seems to identify him also with the Udāyī to whom the Laṭukikopama Sutta (M.i.447 ff) was taught.