The Veda begins with a small book addressed to Agni, Indra, Soma and other gods, all arranged according to decreasing total number of hymns in each deity collection; for each deity series, the hymns progress from longer to shorter ones, but the number of hymns per book increases. If thou, O Agni, God, accept it gladly, may we obtain thereby the heavenly Waters".  The Śākala recension has 1,017 regular hymns, and an appendix of 11 vālakhilya hymns which are now customarily included in the 8th mandala (as 8.49–8.59), for a total of 1028 hymns. Some of these texts have survived, most lost or yet to be found. The last, or the 10th Book, also has 191 hymns but 1754 verses, making it the second largest. , Several shakhas ("branches", i. e. recensions) of Rig Veda are known to have existed in the past. The Vedas are a large body of Hindu texts originating in ancient India, with its Samhita and Brahmanas complete before about 800 BCE. ed. BN Krishnamurti Sharma (2008), A History of the Dvaita School of Vedānta and Its Literature, Motilal Banarsidass.  Each Veda has four subdivisions – the Samhitas (mantras and benedictions), the Aranyakas (text on rituals, ceremonies, sacrifices and symbolic-sacrifices), the Brahmanas (commentaries on rituals, ceremonies and sacrifices), and the Upanishads (texts discussing meditation, philosophy and spiritual knowledge). Wilson also translated this book into English as Rigveda Sanhita in the year 1856. Ruse (2015) commented on the old discussion of "monotheism" vs. "henotheism" vs. "monism" by noting an "atheistic streak" in hymns such as 10.130. ", The emphasis in this transmission[note 9] is on the "proper articulation and pronunciation of the Vedic sounds," as prescribed in the Shiksha, the Vedanga (Vedic study) of sound as uttered in a Vedic recitation, mastering the texts "literally forward and backward in fully acoustic fashion. Paul Kuritz (1988), The Making of Theatre History, Prentice Hall. [note 8] As Leela Prasad states, "According to Shankara, the "correct tradition" (sampradaya) has as much authority as the written Shastra," explaining that the tradition "bears the authority to clarify and provide direction in the application of knowledge. [note 1] According to Michael Witzel, the codification of the Rigveda took place at the end of the Rigvedic period between ca. They were memorized and verbally transmitted with "unparalleled fidelity" across generations for many centuries. These hymns present the imagery of being in heaven as "freedom, joy and satisfaction", a theme that appears in the Hindu Upanishads to characterize their teachings of self-realization. Hindus consider the Vedas to be apauruṣeya, which means "not of a man, superhuman" and "impersonal, authorless," revelations of sacred sounds and texts heard by ancient sages after intense meditation.  H.D. 275–289; Edwin Bryant (2004), The Quest for the Origins of the Vedic Culture, Oxford University Press. Michael Witzel (2003), "Vedas and Upaniṣads", in The Blackwell Companion to Hinduism (Editor: Gavin Flood), Blackwell.  The Atharvaveda was not considered as a Veda in the Vedic era, and was accepted as a Veda in late 1st millennium BCE.  The term áyas (metal) occurs in the Rigveda, but it is unclear which metal it was.  The Yajur Veda has been the primary source of information about sacrifices during Vedic times and associated rituals.  Each school likely represented an ancient community of a particular area, or kingdom. Vedas are śruti "what is heard"), distinguishing them from other religious texts, which are called smṛti ("what is remembered"). A metrically restored text.  The Rigveda, or other Vedas, do not anywhere assert that they are apauruṣeyā, and this reverential term appears only centuries after the end of the Vedic period in the texts of the Mimamsa school of Hindu philosophy.  According to Staal, criticising the Goody-Watt hypothesis "according to which literacy is more reliable than orality," this tradition of oral transmission "is closely related to Indian forms of science," and "by far the more remarkable" than the relatively recent tradition of written transmission. , Vedangas developed as ancillary studies for the Vedas, but its insights into meters, structure of sound and language, grammar, linguistic analysis and other subjects influenced post-Vedic studies, arts, culture and various schools of Hindu philosophy.