Sayyiduna al-Ash'ath bin Qays (may Allah be pleased with him) said: A man from the Hadramis brought a dispute over his land before the Prophet (peace and blessings be upon him) against a man from among us called al-Hafshish. The Prophet (peace and blessings be upon him) said to the Hadrami: "Bring your witnesses for your right; otherwise he will swear an oath for you." He said: My land is far too great a matter for him not to swear over it. The Messenger of Allah (peace and blessings be upon him) said: "The oath of a Muslim has behind it something even greater than that." So he (al-Hafshish) set off to take the oath, and the Messenger of Allah (peace and blessings be upon him) said: "If he swears falsely, Allah, the Mighty and Majestic, will enter him into Hellfire." So al-Ash'ath went and told him this, and he said: Make peace between me and him. So peace was made between them.
Hadith Referenceالمعجم الكبير للطبراني / باب الألف / 634