According to Tafsir al-Tibyan 3/413...

According to Tafsir al-Tibyan 3/413, `Abdullah ibn `Umar said, ‘Surah of al-Ma`idah was the final.’ In al-Ghadir 1/228, we read the following: Ibn Kathir has narrated on the authority of Ahmad, al-Hakim and al-Nassa`i that `A`ishah said, ‘Surah of al-Ma`idah was the final.’ To sum it up, the , as well as many authentic narrations recorded in Sunni reference book of Hadith, have confirmed that Surah of al-Ma`idah was the final and the Verse of Ikmal al-Din was the final revelation because it shows that the religion has been perfected.

The Other Opinions Although the question of the Verse of Ikmal al-Din’s being the final is logically and practically indisputable, it was obscured because of the many conflicting, yet authentic according to their criteria, narrations each identifying a definite Verse as the final. The matter became worse when some Sahabah adopted certain opinions in this regard, and the Sahabah’s personal opinions are always too faultless to be objected! Unlike the four…