Islamic scholars agree that without knowing the Arabic language and its disciplines it is impossible to completely understand the Qur’an. In that sense they emphasise that valid are those meanings of the Arabic language from the time of the revelation of the Qur’an, since the Arabic language, as every other language, is capable of changes that are the result of cultural, social, scientific and other stirrings, and since some words can change their meaning over time. In order to interpret the Qur’an correctly, one needs meanings that were present in the time of revelation of the Qur'an and not those that occurred later. If that was not the case, then there would be more space for wrong interpretation of the Qur'anic text. Having in mind the above mentioned, it becomes clear that Arabic poetry from the time of the revelation of the Qur'an is a significant source for understanding meanings of many words and terms used in the Qur'anic text. That is why a distinguished mufassir from the generation of companions, Abdullah ibn Abbas, emphasised the importance of Arabic poetry, which he called diwan (archive) of Arabs. In this paper the author writes about the significance of classic Arabic poetry for interpreting the Qur’an. Categories of poets whose opuses were used for tafseer are mentioned, together with their biographies and numerous examples which show how broad relying on poetry can be, which is evident in linguistics, grammar, flexion, etc. Historical-analytic method was mainly used. Keywords: tafseer, poetry, categories of poets, Imru' al-Qais, An-Nabiga, Al-A'sha, aims for using poetry as an example