http://www.hindunet.org/saraswati/aryans.pdf
Ths URL is a six-page extract from FBJ Kuiper's 1991 book to show the
extent to which the language of the R.igveda can be explained in
terms of the impact of substratum languages.
This lends significant evidence, in my view, to contest that `IE
speakers' came from outside India. It is quite likely that they were
long-time residents and hence, had assimilated a number of influences
from the substratum languages and cultural mores. The explanations of
the impact of R.gvedic Sanskrit on Avestan and other Indo-European
languages may have to be found from a series of migrations of early
IE speakers.
This is to some extent corroborated by the evidence of the Kayanians
in ancient Iran. "The Kavis of the Yashts later became the dynasty of
the Kayanians which, occupies, amont the historians of Persia, an
important place in the history of antiquity, they precede the
Achaemenians whom one has placed in genealogical relation with them
In the Gathas, Vishtaspa, the most powerful of the adherents and
assistants of Zoroaster, of ten bears the title of kavi which has the
significance of `king' in the east-Iranian native land of
Zoroastraianism. Vishtaspa is the only kavi who has taken sides with
the Prophet. When the Gathas mention the kavis in the plural, it is a
question of enemy princes who follow the daevic religion against
which Zoroaster fought; and if the younger Avesta sometimes
designates the enemy princes of the faith as kavis/(`the kavis and
the karapans') then it is an intimation of the Gathic language which
most often has no relation with the political and social conditions
of the times in which the passage was composed...Sasanian king Kavad
I. Kavad himself, born in the middle of the 5th century AC, bears the
name of the first Kavi (Kavata Kavad); theee of his sons are named
Kaus (=Kavi Usan), Khusrav (Haosravah) and Jam (Yima)." (Arthur
Christensen, 1993, The Kayanians (Les Kayanides), Bombay, KR Cama
Oriental Institute, pp. 5-8, 39). This is a legacy from the R.gveda,
the Kavi us'anas is the name of a r.s.i whose hymns are celebrated in
the Rigveda Sam.hita_. In the Iranian tradition, kavi-s are smiths
who became kings. It is possible to explain the central process of
the R.gveda related to Soma processing as a metallurgical allegory of
purifying electrum quartz/pyrites to yield pure gold and silver.