Chandogya Upanishad

One of the oldest and longest Upanishads, attached to the Samaveda and mixing exegesis of chant with some of the most quoted philosophy in the tradition, including Uddalaka Aruni's instruction to his son Shvetaketu culminating in 'tat tvam asi.' It also tells of Satyakama Jabala, admitted to study despite not knowing his father's lineage, an early gesture toward valuing truthfulness over inherited status. A separate section preserves the dialogue between the creator-god Prajapati and his pupils Indra and Virochana over the true nature of the self, in which Virochana settles too quickly for the mistaken answer that the reflected body is the self, while Indra persists through several false starts until he grasps something closer to the text's own teaching. Its precise place of composition within the wider Kuru-Panchala region remains uncertain.