Musnad Ahmad 25:805

Yunus ibn Muhammad narrated to us, Abd al-Wahid—meaning Ibn Ziyad—narrated to us, Layth narrated to us, from Tawus, from Ibn Abbas, who said: "The Messenger of Allah (ﷺ) performed Tamattu' until he died, and Abu Bakr until he died, and Umar until he died, and Uthman until he died. And the first one to forbid it was Mu'awiyah." Ibn Abbas said: "So I was amazed at him, for he had told me that he had trimmed the hair of the Messenger of Allah (ﷺ) with a pair of scissors."