Musnad Ahmad 25:895

Aswad narrated to us, Sharik narrated to us, from Abu Ishaq, from al-Dahhak, from Ibn Abbas, who said: The Talbiyah of the Prophet, peace and blessings of Allah be upon him, was: "Labbayk Allahumma Labbayk, Labbayka la sharika laka Labbayk, inna al-hamda wa an-ni'mata laka wa al-mulk, la sharika lak." (At Your service, O Allah, at Your service. At Your service, You have no partner, at Your service. Indeed, all praise and grace are Yours, and the dominion; You have no partner.)