Musnad Ahmad 32:18

Hashim narrated to us, Yahya ibn Abi Ishaq, and Abd al-Aziz ibn Suhayb, and Humayd al-Tawil informed us, from Anas ibn Malik, that they heard him saying: I heard the Messenger of Allah, peace and blessings of Allah be upon him, pronouncing the Talbiyah for Hajj and Umrah together, saying: "Labbayk, Umrah and Hajj; Labbayk, Umrah and Hajj."