Caliphs..

'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." '

- Sahih Bukhari Vol.2, hadith 634