Who was the first to author a work on the science of Quranic exegesis (Tafsir)?

The science of Tafsir (definition) (exegesis of the Quran) existed since the era of the Prophet, peace and blessings be upon him. The Companions would ask him about matters that were unclear to them. Schools of Tafsir were established in Makkah, Madinah, and other places. However, the formal codification (tadwin) of Tafsir came later, during the late Umayyad period and early Abbasid period, and it passed through three stages:

1. The first stage: Tafsir was compiled within books of Hadith (definition), such as those by Yazid ibn Harun and Wakee' ibn al-Jarrah. 2. The second stage: Tafsir was isolated and authored as an independent science, exemplified by Ibn Jarir al-Tabari and Ibn al-Mundhir. This stage was characterized by the mention of isnads (chains of narration). 3. The third stage: Tafsir by opinion (al-ra'y) or Tafsir by transmitted narrations (al-ma'thur) with abbreviated isnads, such as Al-Kashshaf by Al-Zamakhshari. Caution must be exercised regarding its contents due to the presence of weak hadith or Mu'tazilite views.