1. Udāyī Thera.– 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-
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.
2. Udāyī.– A thera. It was once his turn to recite the Pāṭimokkha before the Saṅgha, but because he had a crow’s voice (kākasaraka), he had to obtain permission to make a special effort so that his recitation might be audible to the others (Vin.i.115). It is, perhaps, this same monk who is mentioned in the Vinaya as having been guilty of numerous Saṅghādisesa offences (Vin.iii.110 f, 119 f, 127 f, 137 f, 135 ﬀ).
He is censured again and again and various penalties are inflicted on him, nevertheless he repeats his offences (Vin.ii.38 ﬀ). In the section on offences requiring forfeiture (Nissaggiyakaṇḍaṃ) (Vin.iii.205 f) a story is told of a nun, a former mistress of Udāyī, who conceived a child through touching a garment worn by him. Once when Uppalavaṇṇā asked him to take some meat to the Buddha, he demanded her inner robe as his fees (Vin.iii.208). He seems to have been very fond of the company of women and they returned his liking. (See, e.g., Vin.iv.20, 61, 68). There was evidently a strain of cruelty in him, for we are told of his shooting crows and spitting them with their heads cut off (Vin.iv.124). He is described as being fat (Vin.iv.171). He is perhaps to be identified with Lāḷudāyī.
3. Udāyī.– A brahmin. He visited the Buddha at Sāvatthi and asked if the Buddha ever praised sacrifice. The Buddha’s answer was that he did not commend sacrifices that involved butchery, but praised those that were innocent of any killing (A.ii.43 f).
4. Udāyī.– See also under Kāludāyī, Lāḷudāyī, and Sakuludāyi. As they are all, from time to time, referred to as Udāyī it is not always possible to ascertain which is meant. The Commentary is not an infallible guide.