I made a vow to marry if I succeeded, but I did not fulfill it?

Scholars differed regarding one who vows an permissible matter. Imam Ahmad was of the opinion that he has the choice between fulfilling the vowed matter or offering an expiation for an oath. Others held that a vow concerning a permissible matter is not binding and entails nothing, citing marriage and gifts as examples. Shafi'i jurists differed on whether a vow to marry is binding or not. The more preponderant opinion is that it is not binding, and it is preferable to offer an expiation for an oath.