What is the expiation for one who swore "By Allah the Almighty" exaggeratingly, twisting his tongue with a lie, and was unable to retract his words?

The Ghamus Oath is a deliberately false oath. Sincere repentance is required for it, and according to the majority of scholars, there is no expiation for it. The Shafi'is, however, are of the opinion that expiation is obligatory for it. As a precautionary measure, it is advisable to offer an expiation for an oath to avoid scholarly disagreement.