"I heard 'Umar say" 'By Allah, I forbid you to forbid you to perform Tamattur,' but it is mentioned in the Book of Allah and the Messenger of Allah did it" meaning 'Umrah with Hajj.
Sunan an-Nasa'i Book 24, Hadith 118
← Previous Hadith he used to issue Fatwas concerning Tamattu' Then a man said to him: "Withhold some of your Fatwas ,for you do not know what the commander of the Believers introduced into the rites subsequently." Then when I met him, I asked him. 'Umar said: "I know that the Messenger of Allah and his companions did it, but I did not like that people should lay with their wives in the shade of the Arak trees, and then go out for Hajj with their heads dripping."

Sunan an-Nasa'i Book 24, Hadith 117 Next Hadith → "Mu'awiyah saide to Ibmn 'Abbas: "do you know that I cut the hair of the Messenger of Allah at Al-Marwah?" He said: "No." Ibn 'Abbas said: "This Mu'awiyah forbids the people to perform Tamattu' but the Prophet performed Tamattue."

Sunan an-Nasa'i Book 24, Hadith 119