Musannaf Ibn Abi Shayba 36:400

Ibn ‘Uyaynah narrated to us, from al-Zuhri, from ‘Ubayd Allah, from Ibn ‘Abbas, that the Prophet (may Allah bless him and grant him peace) fasted in the year of the Conquest until he reached al-Kadid, then he broke his fast. And the latter of the actions of the Messenger of Allah (may Allah bless him and grant him peace) is what is to be taken.