Musnad Ahmad 943:1

Abu Mu'awiyah narrated to us, Al-A'mash narrated to us, from Shaqiq, from Abdullah, who said: The Messenger of Allah (peace and blessings of Allah be upon him) said: "Whoever swears an oath in which he is a liar, in order to seize the property of a Muslim man by it, he will meet Allah while He is angry with him." Al-Ash'ath said: "By Allah, it was about me that this happened. There was a piece of land between me and a man from the Jews, and he denied my claim. So I brought him before the Prophet (peace and blessings of Allah be upon him), and the Messenger of Allah (peace and blessings of Allah be upon him) said: 'Do you have evidence?' I said: 'No.' He said to the Jew: 'Swear an oath.' I said: 'O Messenger of Allah, if he swears, he will take my property.' Then Allah the Exalted revealed: 'Indeed, those who exchange the covenant of Allah and their oaths for a small price' [Al-Imran: 77] to the end of the verse."