Musnad Ahmad 215:6

Abu al-Nadr narrated to us, he said: Abd al-Samad ibn Habib ibn Abdullah al-Azdi, then al-Awdi, narrated to us, he said: Habib ibn Abdullah—meaning his father—narrated to me, he said: I heard Sinan ibn Salamah ibn al-Muhabbaq al-Hudhali narrating from his father, he said: The Messenger of Allah, peace and blessings of Allah be upon him, said: "Whoever possesses a beast of burden that finds its way to satiety, let him fast Ramadan wherever it reaches him."