It is narrated from Sayyiduna Ibn Abbas (may Allah be pleased with them both) that Mu'awiyah (may Allah be pleased with him) (asked) about tamattu' in Hajj, and Ibn Abbas (may Allah be pleased with them both) said: The Messenger of Allah (peace and blessings be upon him) did it.
Hadith Referenceالمعجم الكبير للطبراني / باب العين / 10693