Hadith 6696
Narrated `Aisha: The Prophet said, "Whoever vows that he will be obedient to Allah, should remain obedient to Him; and whoever made a vow that he will disobey Allah, should not disobey Him."
Hadith 6700
Narrated `Aisha: The Prophet said, "Whoever vowed to be obedient to Allah, must be obedient to Him; and whoever vowed to be disobedient to Allah, should not be disobedient to Him."