Musannaf Ibn Abi Shayba 3:3244

Yazid ibn Harun narrated to us, from Ibn Abi Dhi'b, from al-Zuhri, that the Messenger of Allah (may Allah bless him and grant him peace) used to go out on the day of al-Fitr and recite the takbir until he reached the prayer ground and until he finished the prayer. When he finished the prayer, he would cease the takbir.