Upanishads

"The Upaniṣads are among the most sacred foundational scriptures in the Hindu religion. Written from 800 BCE onward and making up part of the larger Vedic corpus, they offer the reader "knowledge lessons" on life, death, and immortality. While they are essential to understanding Hinduism and Asian religions more generally, their complexities make them almost impenetrable to anyone but serious scholars of Sanskrit and ancient Indian culture."--