Sayyiduna Imran bin Husayn (may Allah be pleased with him) narrates from the Prophet (peace and blessings be upon him) that the Prophet (peace and blessings be upon him) said: "There is no vow in disobedience, and its expiation is that of an oath."
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الأيمان / 20067