From Sahih Bukhari (Hadith 4518):
Narrated `Imran bin Husain:The Verse of Hajj-at-Tamattu was revealed in Allah's Book, so we performed it with Allah's Messenger (ﷺ), and nothing was revealed in Qur'an to make it illegal, nor did the Prophet (ﷺ) prohibit it till he died. But the man (who regarded it illegal) just expressed what his own mind suggested
Reference: Bukhari 4518