If one breaks an oath, is atonement immediately incumbent upon him?

The majority of scholars are of the opinion that expiation must be performed immediately upon breaking an oath. This is the fundamental principle for an absolute command. The Shafi'is, however, hold that it is obligatory with delay, although some of them are of the opinion that it is immediately obligatory if the breaking of the oath was a sin. The most preponderant view is that it is immediately obligatory for whoever is able to perform it.