ABROGATION OF AN OATH
Allah Himself allowed abrogation of oaths if need be. �God has already ordained for you the dissolution of your oaths� (QurAn 66:2).
A vow which is in disobedience to Allah or which is taken for un-Islamic ends is not to be fulfilled. Muslim jurists differ as to whether a vow taken during the days of ignorance (i.e., before one embraces Islam) is binding or not. Some hold that such a vow should be fulfilled if it is not against the teachings of Islam.
An oath can be broken, particularly if the oath-taker finds something better to do. �He who took an oath, but he found something else better than that, should do that which is better and break his oath,� says Muhammad (4057). Some people once asked Muhammad to provide them with mounts. Muhammad swore: �By Allah, I cannot provide you a mount.� But immediately after they were gone, he called them back and offered them camels to ride. Muhammad explained: �So far as I am concerned, by Allah, if He so wills, I would not swear, but if later on, I would see better than it, I would break the vow and expiate it and do that which is better� (4044).