From a linguistic point of view, these treatises with their appendages, the more mystic and recondite Aranyakas and the speculative Upanishads, have to be considered as forming the connecting link between the Vedic and the classical Sanskrit.
He shows that in the 3rd century B.C. the language used throughout northern India was practically one, and that it was derived directly from the speech of the Vedic Aryans, retaining many Vedic forms lost in the later classical Sanskrit.
Hence, in the later classical Sanskrit literature, the term dvija, or twice-born, is used simply as a synonym for a Brahman.
