Shruti

(“[that which is] heard”) The most
authoritative type of Hindu sacred literature, made up of all the Vedas, the oldest Hindu religious texts. The Vedas are
generally considered to have four types
of texts: the hymns to the gods known as
samhitas, the ritual manuals called the
Brahmanas, and the speculative texts
known as the Aranyakas and the
Upanishads. The term comes from the
traditional Hindu belief that these texts
were not composed by human beings
but are based in the primordial vibrations of the cosmos itself. The ancient
sages, whose faculties of perception had
been sharpened through persistent religious practice, were able to “hear” and
understand these vibrations, and transmitted them to others in a lineage of
learning. Thus, the belief that their origin is nonhuman makes the shruti the
highest religious authority.