It is narrated from Marwan bin Hakam that once I was present between Makkah and Madinah with Sayyiduna Uthman Ghani and Sayyiduna Ali (may Allah be pleased with them). Sayyiduna Uthman Ghani (may Allah be pleased with him) used to prohibit Hajj Tamattu', that is, combining Hajj and Umrah in the same journey. Seeing this, Sayyiduna Ali (may Allah be pleased with him) put on the Ihram for both. Sayyiduna Uthman (may Allah be pleased with him) said to him, "Are you not aware that I have issued the order prohibiting this, and yet you are still doing it?" He replied, "But I cannot leave the word of the Prophet (peace and blessings be upon him) for the word of anyone else."