Musnad Ahmad 4335

It was narrated that Ibn Mas'ood said: I heard a man narrate a verse that I had heard differently from the Prophet (ﷺ) and I brought him to the Prophet (ﷺ). Then I recognised displeasure in the face of the Prophet (ﷺ). He said: "Both of you are good; do not differ.” As far as I (the narrator) know, Mis’ar said: He said: "Do not differ, for those who came before you differed and they were doomed.”