Musannaf Ibn Abi Shayba 7:5

Ibn Fudayl narrated to us, from al-Nu’man ibn Qays, from his maternal aunt Mulaykah, from ‘Ubaydah, who said: I asked him about the vow (nadhr), and he said: "Whatever vow is for something that is an act of obedience to Allah, then fulfill it. And whatever vow is for something that is an act of obedience to Satan, then do not permit it."