Al-Bukhārī’s wording is (1): “‘Alī and ‘Uthmān disagreed over tamattu‘ while they were at ‘Usfān. ‘Alī said: ‘You seek only to forbid something that the Messenger of Allah, peace and blessings be upon him, did.’ When ‘Alī saw this, he entered ihrām for both together.”
Al-Bukhārī alone related (2) the report of Marwān ibn al-Hakam, who said: “I was present with ‘Alī and ‘Uthmān while ‘Uthmān was forbidding tamattu‘ and combining the two. When ‘Alī saw this, he entered ihrām for both, saying: ‘Here I am at Your service for ‘umrah and Hajj.’ He then said: ‘I would not abandon the sunnah of the Prophet, peace and blessings be upon him, on account of anyone’s words.’”
This shows that they regarded anyone who combined the two as performing tamattu‘, and that this was what the Prophet, peace and blessings be upon him, had done. ‘Uthmān also agreed with ‘Alī that the Messenger of Allah, peace and blessings be upon him, had done this. For when ‘Alī said to him, “Why do you seek to forbid something that the Messenger of Allah, peace and blessings be upon him, did?” he did not reply, “The Messenger of Allah, peace and blessings be upon him, did not do it.” Had he not agreed with him on this, he would have denied it. ‘Alī then intended to act as the Prophet, peace and blessings be upon him, had acted, to follow his example in this, and to demonstrate that his practice had not been abrogated. He therefore entered ihrām for both together, affirming adherence to his example and following him in qirān, and openly demonstrating a sunnah that ‘Uthmān had forbidden on the basis of his interpretation. This, then, is an independent proof, bringing the total to twenty.
The twenty-first proof is what Mālik related from Ibn Shihāb, from ‘Urwah, from ‘Ā’ishah, who said: “We set out with the Messenger of Allah, peace and blessings be upon him, in the year of the Farewell Pilgrimage and entered ihrām for ‘umrah. Then the Messenger of Allah, peace and blessings be upon him, said: ‘Whoever has a sacrificial animal with him should enter ihrām for Hajj along with ‘umrah, and must then remain in ihrām until he is released from both together.’” Mālik related this in al-Muwatta’ (3).