Musnad Ahmad 3882

An-Nazzal bin Sabrah said: I heard a man reciting a verse differently than the way the Messenger of Allah (ﷺ) taught it to me, so I took him by the hand and brought him to the Messenger of Allah (ﷺ), who said: “Both of you are good; do not differ." To the best of my knowledge, or as Mis'ar narrated it to me, “For those who came before you differed concerning it, then they were doomed."