Jāmi` al-bayān `an ta'wīl āy al-Qur'ān, popularly Tafsīr al-Ṭabarī (Arabic: تفسير الطبري‎) is a classic Sunni tafsir

Tafsir

Tafseer is the Arabic word for exegesis or commentary, usually of the Qur'an. Ta'wīl is a subset of tafsir and refers to esoteric or mystical interpretation. An author of tafsir is a mufassir .- Etymology :...

 by the Persian scholar Muhammad ibn Jarir al-Tabari

Muhammad ibn Jarir al-Tabari

Abu Ja'far Muhammad ibn Jarir al-Tabari was a prominent and influential Sunni scholar and exegete of the Qur'an from Persia...

 (838-923). The work is a collective tafsir, very rich in content, and a major source for academic research and historical inquiry.
Tabari finished his work in 883, often dictating sections to his students. It is his second great work after "History of the Prophets and Kings" (Tarīkh al-Rusul wa'l-Muluk), famously known as "Tarikh al-Tabari".
Tabari has primarily used narratives of the Prophet

Hadith

The term Hadīth is used to denote a saying or an act or tacit approval or criticism ascribed either validly or invalidly to the Islamic prophet Muhammad....

, including narrations and comments of the sahabah

Sahabah

In Islam, the ' were the companions, disciples, scribes and family of the Islamic prophet...

 and tabi'in where necessary.