That is in Rikved

The abstract-

The rigveda contains and seems to preserve more common elements from 

the Proto-Indo-European Culture than any other branch of the family. This

essay  examines  various  points  of  language,  poetry  and  philosophy  but  it 

focuses mainly  on  grammatical  elements,  lexical  and syntactical,  and  on 

aspects  of  (fine)  poetry.  This  is  one  aspect  showing  that  Vedic  and  its 

culture  is  much  closer  to  the  PIE  language  and  culture  than  any  other 

branch in that family. Moreover, it shows that it is most unlikely that Vedic 

moved across thousands of miles over difficult terrains to come to rest in 

what is today N-W India and Pakistan, in Saptasindhu or the Land of the 

Seven Rivers. Certain  other  aspects show that Iranian moved  away from

Vedic and Saptasindhu and most probably the other branches did the same 

at  a  very  distant  but  undetermined  period.  Finally, monotheism  is  also  a 

notable feature in the RV despite its pronounced polytheism.

 Also to note the truthfulness of the indologist when he says

''I have not spoken explicitly of the origins of Indian Civilization. It should be obvious, however, 

that I regard the rise of the Vedic Culture as indigenous and not the result of an (Aryan or protoIndo-European) invasion or immigration.

I cannot speak of the origin of this Civilization because I do not know it. And I don’t think 

anybody  else  does.''

so guys say something that comes to your mind.

 link