Bukhari :: Book 2 :: Volume 26 :: Hadith 634
Narrated Marwan bin Al-Hakam:
I saw 'Uthman and 'Ali. 'Uthman used to forbid people to perform Hajj-at-Tamattu' and Hajj-al-Qiran (Hajj and 'Umra together), and when 'Ali saw (this act of 'Uthman), he assumed Ihram for Hajj and 'Umra together saying, "Lubbaik for 'Umra and Hajj," and said, "I will not leave the tradition of the Prophet on the saying of somebody."
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