Is expiation obligatory upon one who said, "By Allah, I only have half of it," while possessing more than that?

If someone swears an oath believing something to be true, but it turns out to be otherwise, this is an unintentional oath (yamin laghw) and requires no expiation (kaffarah). However, if one swears a false oath knowingly, this is a perjurious oath (yamin ghamus), which necessitates repentance, and for which there is no expiation according to the majority of scholars. The Shafi'is and one narration from the Hanbalis, however, hold that expiation is obligatory. For those who wish to be cautious, they should offer the expiation for an oath, which is: feeding ten poor persons, or clothing them, or freeing a slave. Fasting is not sufficient unless one is unable to perform any of these options.