Kikkuli was the Hurrian "master horse trainer" (assussanni, virtually Sanskrit aśva-sana-) of the land Mitanni" (LÚA-AŠ-ŠU-UŠ-ŠA-AN-NI ŠA KUR URUMI-IT-TA-AN-NI) and author of a chariot horse training text written in the Hittite language, dating to the Hittite New Kingdom (around 1400 BCE). The text is notable both for the information it provides about the development of Indo-European languages and for its content.
This is the text which describes about the languages spoken by the old aryan civilization, when they had kingdoms in those regions.
CTH 284 is the surviving text
CTH 284 consists of four well preserved tablets or a total of 1080 lines. The text is notable for its Mitanni (Indo-Aryan) loanwords, e.g. the numeral compounds aiga-, tera-, panza-, satta-, nāwa-wartanna ("one, three, five, seven, nine intervals", virtually Vedic eka-, tri-, pañca- sapta-, nava-vartana. Kikkuli apparently was faced with some difficulty getting specific Mitannian concepts across in the Hittite language, for he frequently gives a term such as “Intervals” in his own language (somewhat similar to Vedic Sanskrit), and then states, “this means…” and explained it in Hittite.