Musnad Ahmad 22:29

Yahya ibn Zakariya—meaning Ibn Abi Za'idah—narrated to us, saying: Abdul-Malik narrated to me, from Ata, from Ibn Abbas, that the Prophet, peace and blessings of Allah be upon him, let Usamah ibn Zayd ride behind him from Arafah until he reached Jam' (Muzdalifah). And he let Al-Fadl ibn Abbas ride behind him from Jam' until he reached Mina. Ibn Abbas said: And Al-Fadl ibn Abbas informed me that the Prophet, peace and blessings of Allah be upon him, did not cease reciting the Talbiyah until he threw the pebbles at the Jamrah.