Musannaf Ibn Abi Shayba 13:2241

Abu Bakr narrated to us, he said: Abu Mu’awiyah narrated to us, from Bashar ibn Kaddam al-Sulami, from Muhammad ibn Zayd, from Ibn Umar, who said: The Prophet (peace and blessings of Allah be upon him) said: "An oath is either a violation or a regret."