Sarh left Islam and lived in Mecca. Some time later, Muhammad and his army moved on Mecca and took it without a fight.
then he apostatized and returned to Quraysh [Mecca]
'To me it has been revealed', when naught has been revealed to him" refers to 'Abdullah Ibn Sâd Ibn Abi Sarh, who used to write for God's messenger. The verse (23:12) that says, "We created man of an extraction of clay" was revealed, and when Muhammad reached the part that says, "... thereafter We produced him as another creature (23:14), 'Abdullah said, "So blessed be God the fairest of creators!" in amazement at the details of man's creation. The Prophet said, "Write it down; for thus it has been revealed." 'Abdullah doubted and said, "If Muhammad is truthful then I receive the revelation as much as he does, and if he is a liar, what I said is a good as what he said."
He converted to Islam before the conquest of Mecca and immigrated to the Prophet(P) [i.e. in Medina]. He used to record the revelation for the Prophet(P) before he apostatized and went back to Mecca. Then he told Quraysh: 'I used to orient Muhammad wherever I willed, he dictated to me "All-Powerful All-Wise" and I suggest "All Knowing All-Wise" so he would say: "Yes, it is all the same."
The report that conveys the revelation of Chapter 6 entirely in one unit was given from the way of Ubayy Ibn Ka'b, it is weak in its isnâd (i.e. the chain of narration), and I have never seen a trustful (Sahih) isnâd for this tradition. Many traditions even said the contrary i.e. several verses of Chapter 6 were revealed later in Medina. They differed on the number of these verses whether they are 3 or 6 or some other number, and God knows best.
The scribes of Muhammad were 42 in number. 'Abdullah Ibn Sarh al-`Amiri was one of them, and he was the first Quraishite among those who wrote in Mecca before he turned away from Islam. He started saying, "I used to direct Muhammad wherever I willed. He would dictate to me 'All-Powerful, All-Wise' [the critic has wrongly translated 'Aziz by Most-High which is in Arabic 'Aliyy, it seems that he confused it with the previous word 'Alayya which means "to me"], and I would write down 'All-Wise' only. Then he would say, 'Yes it is all the same'. On a certain occasion he said, 'Write such and such', but I wrote 'Write' only, and he said, 'Write whatever you like.'" So when this scribe exposed Muhammad, he wrote in the Qur'an, "And who does greater evil than he who forges against God a lie, or says, 'To me it has been revealed', when naught has been revealed to him."
And I added from various accounts on Sîrah a lot of people, it is for you to verify and check.
They mentioned three who wrote [for the Prophet] and apostatized: Ibn Abî Sarh and Ibn Khatal and another one whose name is unknown. No one of them returned to the religion [Islam] except Ibn Abî Sarh while the others strayed from the right path.
According to Abû Omar, "cAbdullâh Ibn Sâd Ibn Abî Sarh converted back to Islam during the conquest of Mecca and his Islam was fine, and later, his behavior was beyond reproach. He was among the wise and the noble from Quraysh, and was the knight of Banî 'Aamir Ibn Lu'ayy was respected among them. Later, 'Uthmân named him to govern Egypt in the year 25 H. He conquered Africa in the year 27 H and conquered Nuba in the year 31 H and he was the one who signed with the Nubites the armistice that is still valid today. He defeated the Romans in the battle of as-Sawaary in the year 34 H. When he returned from his advent, he was prevented from entering al-Fustât [the capital of Egypt], so he went to 'Asqalân where he lived until the murder of cUthmân(R). It was also said: he lived in Ramlah until he died away from the turmoil. And he prayed Allah saying: "O Allah make the prayer of subh the last of my deeds. So he performed wudu and prayed; he read Surat al-Fâtihah and al-'Aadiyât in the first rak'ah and read al-Fâtihah and another sûrah in the second rak'ah and made salâm on his right and died before he made salâm on the left side. All this report was conveyed by Yazîd Ibn Abî Habîb and others. He didn't pledge allegiance to cAlî nor to Mu'âwiyah (RR). His death was before the people agreed on Mu'âwiyah. It was also said that he died in Africa, but the correct is that he died in 'Asqalân in the year 36 H or 37 H and it was rather said 36 H.
'Abdullah Ibn Sâd Ibn Abî Sarh converted back to Islam before the conquest of Mecca by the Prophet(P).
If this story about Sarh were a fabrication, why did so many early Muslim writers document it? Certainly devout Muslims would not document a lie that serves to undermine their faith.
Let the seeker of knowledge know that Sîrah collects every account whether true or false. But the intention is to mention all that is conveyed in the books of Sîrah regardless of the isnaad. (i.e., the authenticity of the chains of narration)