Two Iranian groups especially Parthian (Parthia [pathava]) and Persians ( Parsa) were exclusively mentioned in the Rigvedic verse 7.83.1. These two groups are mentioned side by side in this Rigvedic verse.
Akaemenian Inscription at Behistun ( Bistun) . C-522-486 B.C.
Script : Persian Cuneiform.
Language : Old Persian ( Avestic).
Location : This tablet was sculptured at Behistun on the main road from Mesopotamia to Persia to commemorate the victory of King Darius (Darayavahush) the Great (c.529-486 BC).
Column one has 96 lines.
In the below Image , you can see first 15 lines of column one.
Column 1 , lines 1-8
1. \ adam \ Dârayavauš \ xšâyathiya \ vazraka \ xšâyatha \ xšâyathiy
2. ânâm \ xšâyathiya \ Pârsaiy \ xšâyathiya \ dahyûnâm \ Višt
3. âspahyâ \ puça \ Aršâmahyâ napâ \ Haxâmanišiya \ thâtiy \
4. Dârayavauš \ xšâyathiya \ manâ \ pitâ \ Vištâspa \ Vištâspahyâ \ pitâ \ Arš
5. âma \ Aršâmahyâ \ pitâ \ Ariyâramna \ Ariyâramnahyâ \ pitâ\ Cišpiš \ Cišp
6. âiš \ pitâ \ Haxâmaniš \ thâtiy \ Dârayavauš \ xšâthiya \ avahyarâ
7. diy \ vayam \ Haxâmanišiyâ \ thahyâmahy \ hacâ \ paruviyata \ âmâtâ \ ama
8. hy hacâ \ paruviyata \hyâ \amâxam \ taumâ \ xšâyathiyâ \ âha \ th
(1) I am Darius [Dâryavuš], the great king, king of kings, the king of Persia [Pârsa], the king of countries, the son of Hystaspes, the grandson of Arsames, the Achaemenid.
(2) King Darius says: My father is Hystaspes [Vištâspa]; the father of Hystaspes was Arsames [Aršâma]; the father of Arsames was Ariaramnes [Ariyâramna]; the father of Ariaramnes was Teispes [Cišpiš]; the father of Teispes was Achaemenes [Haxâmaniš].
(3) King Darius says: That is why we are called Achaemenids; from antiquity we have been noble; from antiquity has our dynasty been royal.
(4) King Darius says: Eight of my dynasty were kings before me; I am the ninth. Nine in succession we have been kings.
(5) King Darius says: By the grace of Ahuramazda am I king; Ahuramazda has granted me the kingdom.
(6) King Darius says: These are the countries which are subject unto me, and by the grace of Ahuramazda I became king of them: Persia [Pârsa], Elam [Ûvja], Babylonia [Bâbiruš], Assyria [Athurâ], Arabia [Arabâya], Egypt [Mudrâya], the countries by the Sea, Lydia [Sparda], the Greeks [Yauna], Media [Mâda], Armenia [Armina], Cappadocia [Katpatuka], Parthia [Parthava], Drangiana [Zraka], Aria [Haraiva], Chorasmia [Uvârazmîy], Bactria [Bâxtriš], Sogdia [Suguda], Gandara [Gadâra], Scythia [Saka] (Ghi-mi-ri or Cimmeria in Babylonian version), Sattagydia [Thataguš], Arachosia [Harauvatiš] and Maka [Maka]; twenty-three lands in all.
(7) King Darius says: These are the countries which are subject to me; by the grace of Ahuramazda they became subject to me; they brought tribute unto me. Whatsoever commands have been laid on them by me, by night or by day, have been performed by them.
(8) King Darius says: Within these lands, whosoever was a friend, him have I surely protected; whosoever was hostile, him have I utterly destroyed. By the grace of Ahuramazda these lands have conformed to my decrees; as it was commanded unto them by me, so was it done.
(9) King Darius says: Ahuramazda has granted unto me this empire. Ahuramazda brought me help, until I gained this empire; by the grace of Ahuramazda do I hold this empire.