They are alone allowed to read the veda or Sacred Books.
"Narrative of a Voyage to India; of a Shipwreck on board the Lady Castlereagh; and a Description of New South Wales"
W. B. Cramp
Two-fifths of the hymns of the Rigveda are composed in a metre called trishtubh, the most frequent measure in the veda.
"The Literature of Ecstasy"
Albert Mordell
The third of the five Gathas uses the trishtubh or most frequent metre of the veda, four lines of eleven syllables, but without restrictions as to quantity of final vowels.
"The Literature of Ecstasy"
Albert Mordell