Is expiation obligatory for one who lied under oath to save someone from embarrassment?

A deliberate false oath concerning a past event is the "Yamin al-Ghamus" (the diving oath). There is a difference of opinion regarding the necessity of expiation (kaffarah) for it. The majority of scholars do not obligate expiation, considering it too grave to be expiated, while the Shafi'is obligate it. The fatwa (religious edict) given follows the opinion of the majority, thus no expiation is required; rather, repentance to Allah is obligatory.