Musnad Ahmad 943:5

Ziyad ibn Abdullah ibn al-Tufayl al-Baka’i narrated to us, Mansur narrated to us, from Shaqiq, from Abdullah ibn Mas’ud, who said: "Whoever swears a false oath (*yamin sabr*) by which he unjustly acquires property while he is a sinner in it, he will meet Allah while He is angry with him." And the confirmation of that is in the Quran: "Indeed, those who exchange the covenant of Allah and their oaths for a small price" [Al-Imran: 77] to the end of the verse. He said: Then al-Ash’ath went out, and he was reciting it. He said: "Regarding me was this verse revealed. A man claimed a well of mine, so we disputed before the Messenger of Allah (peace and blessings of Allah be upon him). He said: 'Your two witnesses, or his oath.' I said: 'But if he swears, he will swear falsely.' Then the Prophet (peace and blessings of Allah be upon him) said: 'Whoever swears a false oath by which he unjustly acquires property, he will meet Allah while He is angry with him.'"