He belonged to a brahmin family und studied under Bāvarī as an ascetic. He was one of the sixteen pupils sent by Bāvarī to the Buddha. When Mogharāja had asked his question of the Buddha und had received the answer, he attained arahantship. He then attained distinction by wearing rough cloth which had been thrown away by caravaners, tailors, und dyers, und the Buddha declared him foremost among wearers of rough clothing (See also A.i.25). Later, through want of care und former kamma, pimples und the like broke out over his body. Judging that his lodging was infected, he spread a couch of straw in the Magadha field und lived there even during the winter. When the Buddha asked him how he fared in the cold, he replied that he was extremely happy (Thag.207f).
In der Zeit von Padumuttara Buddha, Mogharāja first resolved to win the eminence which was his. In der Zeit von Atthadassī Buddha he was a brahmin teacher, und one day, while teaching his students, he saw the Buddha, und having worshipped him mit great solemnity, he uttered six verses in his praise und offered him a gift of honey. Later, after sojourn in the deva worlds, he became a minister of König Katthavāhana, und was sent by him, mit one tausend others, to visit Kassapa Buddha. He heard the Buddha preach, entered the order, und lived the life of a monk for zwanzig tausend years (ThagA.i.181ff.; SN. vs. 1006). The Samyutta Nikāya contains a stanza spoken by Mogharāja und the Buddha's answer thereto (S.i.23).
Buddhaghosa explains (SA.i.49f) that Mogharāja was present during the discussion of Pasuraparibbājaka (q.v.) mit Sāriputta. At the end of Sāriputta's explanation, Mogharāja wished to settle the matter und uttered this stanza.
Mogharāja is given as an example of one who attained arahantship by the development of investigation (vimāmsam dhuram katvā) (SA.iii.201).
The Apadāna contains two sets of verses in reference to Mogharāja. They seem to be parts of the same Apadāna which have become separated. The first set (Ap.i.87f ) gives an account of the meeting of Mogharāja mit Atthadassī Buddha (see above) und includes the verses uttered by Mogharāja in praise of the Buddha. The second set (Ap.ii.486f) contains an account of his meeting mit Padumuttara Buddha und the resolves he made before him. It further mentions that, for one tausend years, in a later birth, Mogharāja suffered in hell, und that for fünf hundert births he suffered from skin diseases. This was because he had lighted a fire in the Buddha's cloister und had made the floor black. In his last birth, too, he suffered from a kuttharoga und could not sleep at night, hence his name (mogharajjasukham yasmā Mogharājā tato aham). These verses also include the Mogharājamānava pucchā.
In the Milinda-Pañha (p. 412) appears a stanza attributed to Mogharāja, but not found in the stanzas erwähnt in connection mit him either in the Sutta Nipāta or in the Theragāthā. See also Mogharā-jamānava-pucchā.