Sayf at-Tamimi in his “ar-Ridda wal-Futuh wal Kitab al-Jamal” (p 53) narrated with his chain till Suwayd ibn Qaflatah:
I heard Ali ibn Abi Talib – alaihi salam – said: O people! Allah, Allah, beware (about Him and about) extremism regarding Uthman and your words about him: The one who burned the scripts! BY ALLAH, HE DIDN’T BURN THEM EXCEPT BY ADVICE OF ALL COMPANIONS OF MUHAMMAD, ALL OF THEM. He (Uthman) said: What do you say about this variant of reading that people differ in? Man comes to man and says: My recitation is better that your recitation, and my recitation is better (afdal) that your recitation. And this is resemblance to disbelievers. We (Ali says this) said: What is your opinion O COMMANDER OF FAITHFUL? He said: I see that (we should) gather people around one script, and if you differ this day, the day after yours the difference would be greater. (Ali said) and we said: What a good opinion.
The same text this report was transmitted by ibn Abi Dawud in “al-Masahif” (1/77), and it was authenticated by al-Hafidh in “Fath al-Bari” (9/18).