Sayyiduna Abdullah (may Allah be pleased with him) said: I kept watching the Prophet (peace and blessings be upon him); he (peace and blessings be upon him) kept saying the Talbiyah until he threw the first pebble at Jamrat al-Aqabah.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الحج / 9603