they then differed, as stated in Surah Yūnus and likewise in the reading of some of the Companions.
According to the reading of the majority of the Companions and Successors, this means that they had followed the religion of Islam. Ibn Atiyya’s Tafsīr, however, relates from Ibn Abbas that they had followed disbelief(1). This view is untenable. The report attributed to Ibn Abbas in Ibn Atiyya’s Tafsīr is not authentically established from him. Rather, it is authentically established that he said, “Between Adam and Noah were ten generations, all of whom followed Islam.”
Allah also said in Surah Yūnus:
“Humanity was once but one community, but then they differed.”
[Surah Yūnus: 19]
Thus, He condemned them for differing after they had followed one religion, demonstrating that it had been the truth.
The term “differing” is used in the Book of Allah in two ways. The first is when all the parties are blameworthy, as in His words:
“Indeed, those who differ concerning the Scripture are in profound dissension.”
[Surah al-Baqarah: 176]
The second is when some follow the truth and others follow falsehood, as in His words:
“We favored some of those messengers above others. Among them were those to whom Allah spoke, and He raised some of them in rank. We gave Jesus, son of Mary, clear proofs and supported him with the Holy Spirit. Had Allah willed, those who came after them would not have fought one another after the clear proofs had come to them. Yet they differed: some of them believed, while others disbelieved. Had Allah willed, they would not have fought one another, but Allah does whatever He wills.”