Hindu texts "Śruti" refers to the body of most authoritative, ancient religious texts, believed to be eternal knowledge authored neither by human nor divine agent but transmitted by sages ("rishis"). These comprise the central canon of Hinduism. It includes the four Vedas including its four types of embedded texts - the Samhitas, the Brahmanas, the Aranyakas and the early Upanishads. Of the "Shrutis" (Vedic corpus), the Upanishads alone are widely influential among Hindus, considered scriptures par excellence of Hinduism, and their central ideas have continued to influence its thoughts and traditions. The "Smriti" texts are a specific body of Hindu texts attributed
Ancient Iranian religion was strongly connected. Beginning in the early 10th-century BC, the ancient Iranian religion was gradually displaced by Zoroastrianism, which contains many essential aspects of its predecessor. The sources on ancient Iranian religion, though limited, consist of textual and material sources. The textual sources are both Iranian and non-Iranian. An important Iranian source is the Avesta, which are Zoroastrian sacred scriptures made in the Avestan. This is considered the principal source of knowledge on ancient Iranian religions. It is a collection of several texts that seems to have been over a large span of time by a variety of authors. These