Who incurs the expiation (Kaffarah) when someone swears an oath concerning another person's action which is then broken?

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The expiation rests upon the person who swore the oath if the person sworn against broke the oath, whether the oath was conditional (e.g., "By Allah, so-and-so will do such-and-such, or not do it") or directed at someone present (e.g., "By Allah, you will do such-and-such"). This is the view held by Ibn Umar, the people of Medina, Ata, Qatadah, Al-Awza'i, the people of Iraq, and Al-Shafi'i. The basis for this is that the swearer is the one who broke the oath (hanith), thus the expiation falls upon him, similar to if he were the actor whose action results in the breaking of the oath. Alternatively, the expiation is due because its cause is either the oath itself, the breaking of the oath, or both, all of which are present in the swearer.