Mahabharata — Shanti Parva, Shloka 76
Āścarya-kathana: Brāhmaṇa–Nāga Dialogue on Sūrya (Vivasvat) and the ‘Second Sun’ Phenomenon
राजसी तामसी चैव व्यामिश्रे प्रकृती स्मृते । तदात्मकं हि पुरुषं जायमानं विशाम्पते
rājasī tāmasī caiva vyāmiśre prakṛtī smṛte | tadātmakaṃ hi puruṣaṃ jāyamānaṃ viśāmpate ||
毗舍摩耶那说：诸性（古那）被记为三种——罗阇（rajas）、昏暗（tamas），以及二者的杂合。人啊，民众之主，一个人出生之时便带着那一性之印记，其禀赋与行止皆由此性所塑成。
वैशम्पायन उवाच
Educational Q&A
Human conduct and temperament are explained through innate dispositions (prakṛti) characterized by the guṇas—rajas, tamas, and mixed forms. A person is said to be born with a nature that conditions tendencies, choices, and ethical struggles, implying that moral cultivation involves recognizing and refining these qualities.
Vaiśampāyana continues a didactic exposition in the Śānti Parva, describing classifications of human nature. He addresses a king (viśāmpati), explaining that people are born with rājasa, tāmasa, or mixed dispositions, setting up guidance on how such natures influence behavior and how they may be understood in the pursuit of dharma.