All "twice-born" males, defined as men born into one of the three "twice-born" categories in Indian society—brahmin, kshatriya, or vaishya—were required to repay three "debts" according to legend.
- The earliest of these obligations was to the gods, for which sacrifices were made.
- The Vedas, the world's oldest and most authoritative religious scriptures, were used to repay the second obligation, which was to the sages.
- The last obligation was to the ancestors (pitrs), which was paid by having a son in order to guarantee that the ancestral ceremonies may continue uninterrupted.