Rāma-Rahasya Upanīshad
Rama eva param brahmam rama eva param tapah Rama eva param tatvam shriramo brahma taarakam (Rama-rahasya Upanishad) Rama is the eternal Brahman, Rama is the divine penance, Rama is the secret crux of everything and Rama is the saviour Brahma . Rāma-Rahasya Upanīshad is a limb of the Àtharva~Veda where Sri Hanūman describes about the various of Sri Rāma and his mantras. A part of the Rama-Rahasya Upanishad : A devotee of Srī Rāma must read the Rāma-Rahasya Upanīshad and devote some time understanding the beautiful and divine essence of Rāma naam and the Rāma~naam mantras. Link to pdf : Rama-Rahasya Upanishad