Musnad Ahmad 27:570

Muhammad ibn Ja'far narrated to us, Shu'bah narrated to us, from Zayd and Abu Bakr, the two sons of Muhammad, that they heard Nafi' narrating from Abdullah ibn Umar, from the Prophet, may Allah bless him and grant him peace, that he used to say: "At-talbiyaka, O Allah, at-talbiyaka. At-talbiyaka, there is no partner for You, at-talbiyaka. Indeed, all praise and grace are Yours, and the dominion; there is no partner for You."