A man who enters ihram for Hajj and Umrah: with which does he begin?

Yahya bin Abi Ishaq narrates that Sayyiduna Anas (may Allah be pleased with him) said that he heard the Messenger of Allah (peace and blessings be upon him) reciting the talbiyah thus: "Labbayka bi-'umratin wa hajj (Here I am for Umrah and Hajj)" (mentioning Umrah first).

Hurayth bin Sulaym said: I heard Sayyiduna Ali (may Allah be pleased with him) recite the talbiyah for Hajj and Umrah together, and he began with Umrah. Sayyiduna Uthman (may Allah be pleased with him) said to him: "You are among those who are looked to (whose practice is taken as a proof)." Sayyiduna Ali (may Allah be pleased with him) said to him: "And you too are among those who are looked to."

Humayd narrates that Sayyiduna Anas (may Allah be pleased with him) said that he heard the Messenger of Allah (peace and blessings be upon him) reciting the talbiyah thus: "Labbayka bi-'umratin wa hajj (Here I am for Umrah and Hajj)" (mentioning Umrah first).

Mansur said: I asked Ibrahim and Mujahid about a man who recites the talbiyah for Hajj and Umrah together. Mujahid said: "He should begin with Umrah."

And Ibrahim said: "His intention suffices him."