As we proceeded in the morning along with AUbs Messenger (ﷺ) from Mina to 'Arafat, some of us prounced Talbiya, and some pronounced Takbir (Allah-o-Akbar).
Sahih Muslim Book 15, Hadith 300
← Previous Hadith We heard 'Abdullah b. Mas'ud saying to the gathering of people (at Muzdalifa) that he had heard Talbiya from him, upon whom Surah al-Baqara was revealed, at this very place. And so he ('Abdullah b. Mas'ud) pronounced Talbiya and we also pronounced it with him.

Sahih Muslim Book 15, Hadith 299 Next Hadith → We were along with Allah's Messenger (way peace he upon him) in the morning of 'Arafa (9th of Dhu'l-Hijja). Some of us pronounced Takbir and some of us Tahlil La ilaha ill-Allah). And to those of us who pronounced Takbir, I said: By Allah, how strange it is that you did not care to ask him: What did you see Allah's Messenger (ﷺ) doing (on this occasion)?

Sahih Muslim Book 15, Hadith 301