“all these geographical notes belonging to diverse hymns are attributed to one and the same poet, SyAvASva, which is indicative of the poet’s travels… - Michael Witzel

“Right from the beginning, in Ṛgvedic times, elaborate steps were taken to insure the exact reproduction of the words of the ancient poets. As a result, the Ṛgveda still has the exact same wording in such distant regions as Kashmir, Kerala and Orissa, and even the long-extinct musical accents have been preserved. Vedic transmission is thus superior to that of the Hebrew or Greek Bible, or the Greek, Latin and Chinese classics. We can actually regard present-day Ṛgveda recitation as a tape recording of what was composed and recited some 3000 years ago. In addition, unlike the constantly reformulated Epics and Purāṇas, the Vedic texts contain contemporary materials. They can serve as snapshots of the political and cultural situation of the particular period and area in which they were composed. […] as they are contemporary, and faithfully preserved, these texts are equivalent to inscriptions. […] they are immediate and unchanged evidence, a sort of oral history ― and sometimes autobiography ― of the period, frequently fixed and ‘taped’ immediately after the event by poetic formulation. These aspects of the Vedas have never been sufficiently stressed […]” (WITZEL 1995a:91).

Something of this fear of the horse and of the thundering chariot, the "tank" of the 2nd millennium B.C. is transparent in the famous horse 'Dadhikra' of the Puru king Trasadasya ("Tremble enemy" in RV 4.38.8) ……..The first appearance of thundering chariots must have stricken the local population with terror similar to that experienced by the Aztecs and the Incas upon the arrival of the iron-clad, horse riding Spaniards.

Book 5 [...] even knows, in a hymn not suspected as an addition, of the Yamunā.