The inscription of Shapur I (Šāpur I) on the wall of the building known as the "KAʿBA-YE ZARDOŠT" (Kaʿba of Zoroaster) located in the historical site of Naqsh-e-Rostam (Naqš-e Rostam) in Fars province is undoubtedly one of the largest and most important historical documents of the early Sassanid dynasty in Iran. This inscription is engraved in three scripts of Parthian language, Middle Persian (Sassanid Pahlavi) and Greek on the three walls of the Kaʿba of Zoroaster. Since the excavation of Naqsh-e-Rostam site and the emergence of this inscription from the heart of the soil, scientists have done a lot of research on it and valuable points about the geographical, political, cultural and military situation of Shapur's reign have been extracted from it. Upon closer inspection of this inscription, it seems that new findings can still be obtained from this valuable inscription, which is far from the keen eye of researchers.
In this research, an attempt is made to provide a more precise meaning to the word nibušt in the Shapur inscription on the Kaʿba of Zoroaster, which has confused many scholars. Thus, the Parthian word nibušt is a special name and corresponds to the term "Dezhnebesht / Deznafesht" (diz [ī] nibišt) in Persian, Arabic and Zoroastrian texts and is probably the name used in the early Sassanid period for the historical collection "Naqsh-e-Rostam". Accordingly, first the word Dez / Dezhnebesht in Persian, Arabic and Zoroastrian texts was examined. Then, the scholars' opinions about the application of the word "Dezhnebesht" in the construction of Kaʿba of Zoroaster and Takht-e Soleyman was presented and reviewed. Then, according to the data and information in the inscription of Shapur I on the Kaʿba of Zoroaster, the term "nibušt" mentioned in this inscription was semantically studied and based on sufficient and logical documents and reasons, the similarity of the word “Dezhnebesht” in the texts of the Islamic period with the and Parthian Pahlavi word “nibušt” in the inscription of Shapur on the Kaʿba of Zoroaster was proved. Also, the semantic and etymological differences between the word "nibušt" and the term "nevešt / writing" were studied.
To achieve these goals, the hypotheses of this research are as follows: 1- The meaning and root of the word "nibušt" is different from the word "nevešt / writing" and in fact "nibušt" is the specific name of a place. 2- The word "nibušt" in the Sassanid period and the term "Dezhnebesht" are the same in the Islamic period, and with the change of the historical period, the word "nibušt" has been used as "Dezhnebesht". 3- The letters "nibušt" (Sassanid period) and "Dezhnebesht" (Islamic period) were the same terms for referring to the historical site of "Naqsh-e-Rostam ". As a result, it seems that the Parthian word nibušt (Greek: νιβυστ), which in the Islamic period had a spelling similar to the word "nebešt" from the root "nevešt / writing", probably caused the historians of this period and even the authors of the Pahlavi religious texts of the Islamic centuries to mistakenly think that this word meant the place where government and religious documents and texts were kept. Thus, by comparing the Iranian scripts (Parthian and Sassanid Pahlavi) and the Greek script of this word in the inscription of Shapur I on the Kaʿba of Zoroaster and also the syntactic analysis of this inscription, it is clear that the word "nibušt" in the Sassanid period and the term “Dezhnebesht” in the Islamic era are the same and over time, the Sassanid word "nibušt" has been used as the word “Dezhnebesht”.