Yahya related to me from Malik that Muhammad ibn Abi Bakr ath-Thaqafi once asked Anas ibn Malik, while the two of them were goingfrom Mina to Arafa, "What did you use to do on this day when you werewith the Messenger of Allah, may Allah bless him and grant him peace?"He said, "Those of us who were saying the talbiya would continue doingso, and no-one disapproved of it, and those of us who were saying'Allahu akbar' would continue doing so, and no-one disapproved of thateither."
USC-MSA web (English) reference: Book 20, Hadith 43
Arabic reference: Book 20, Hadith 748