Musnad Ahmad 790:170

Abdullah ibn al-Walid narrated to us, Sufyan narrated to us, from Muhammad ibn al-Zubayr, from al-Hasan, from Imran ibn Husayn, who said: The Messenger of Allah (peace and blessings of Allah be upon him) said: "There is no vow in disobedience to Allah, nor in anger, and its expiation is the expiation of an oath."