Sahih Bukhari Volume 2, Book 26, Hadith Number 642.

Narated By ‘Imran : We performed Hajj-at-Tamattu’ in the lifetime of Allah’s Apostle and then the Quran was revealed (regarding Hajj-at-Tamattu’) and somebody said what he wished (regarding Hajj-at-Tamattu’) according his own opinion.