Upanisads

The Upanishads (Devanagari: उपनिषद्, IAST: upaniṣad) are regarded as part of the Vedas and as such form part of the Hindu scriptures. They primarily discuss philosophy, meditation, and the nature of God; they form the core spiritual thought of Vedantic Hinduism. Considered as mystic or spiritual contemplations of the Vedas, their putative end and essence, the Upanishads are known as Vedānta ("the end/culmination of the Vedas").
See more at Wikipedia.org...