Passage: The Quran has sparked a huge body of commentary and explication (tafsir), aimed at explaining the "meanings of the Quranic verses, clarifying their import and finding out their significance".Tafsir is one of the earliest academic activities of Muslims. According to the Quran, Muhammad was the first person who described the meanings of verses for early Muslims. Other early exegetes included a few Companions of Muhammad, like ʻAli ibn Abi Talib, ʻAbdullah ibn Abbas, ʻAbdullah ibn Umar and Ubayy ibn Kaʻb. Exegesis in those days was confined to the explanation of literary aspects of the verse, the background of its revelation and, occasionally, interpretation of one verse with the help of the other. If the verse was about a historical event, then sometimes a few traditions (hadith) of Muhammad were narrated to make its meaning clear.Because the Quran is spoken in classical Arabic, many of the later converts to Islam (mostly non-Arabs) did not always understand the Quranic Arabic, they did not catch allusions that were clear to early Muslims fluent in Arabic and they were concerned with reconciling apparent conflict of themes in the Quran. Commentators erudite in Arabic explained the allusions, and perhaps most importantly, explained which Quranic verses had been revealed early in Muhammad's prophetic career, as being appropriate to the very earliest Muslim community, and which had been revealed later, canceling out or "abrogating" (nāsikh) the earlier text (mansūkh). Other scholars, however, maintain that no abrogation has taken place in the Quran. The Ahmadiyya Muslim Community has published a ten-volume Urdu commentary on the Quran, with the name Tafseer e Kabir. Following this commentary, a five volume English commentary was also published as The English Commentary of the Holy Quran.

Question: Who were the companions of Muhammad?
Ali ibn Abi Talib, ʻAbdullah ibn Abbas, ʻAbdullah ibn Umar and Ubayy ibn Kaʻb