Sayyiduna al-Ash'ath bin Qays (may Allah be pleased with him) said: This verse was revealed about me. I had some land that was in the possession of a paternal uncle of mine, so I came to the Messenger of Allah (peace and blessings be upon him), and he (peace and blessings be upon him) said: "Bring your evidence, or else (the case will be decided by) his oath." I said: O Messenger of Allah! Then he will swear. The Messenger of Allah (peace and blessings be upon him) said: "Whoever takes a binding (decisive) oath by which he seizes the property of a Muslim man, while he is lying in it, will meet Allah, the Mighty and Majestic, while He is angry with him." So Allah, the Mighty and Majestic, revealed this verse: "Indeed, those who sell the covenant of Allah and their oaths for a small price" [Surah Al Imran: 77], to the end of the verse.
Hadith Referenceالمعجم الكبير للطبراني / باب الألف / 636