The Prophet (ﷺ) said, "The people of my generation are the best, then those who follow them, and then whose who follow the latter. After that there will come some people whose witness will go ahead of their oaths, and their oaths will go ahead of their witness." Ibrahim (a sub-narrator) said, "We used to be beaten for taking oaths by saying, 'I bear witness by the Name of Allah or by the Covenant of Allah."
Allah's Messenger (ﷺ) said, "If somebody takes a false oath in order to get the property of a Muslim (unjustly) by that oath, then Allah will be angry with him when he will meet Him." Al-Ash'ath informed me, "By Allah! This was said regarding me. There was a dispute about a piece of land between me and a man from the Jews who denied my right. I took him to the Prophet. Allah's Messenger (ﷺ) asked me, 'Do you have…
A man displayed some goods in the market and took a false oath that he had been offered so much for them though he was not offered that amount Then the following Divine Verse was revealed:-- "Verily! Those who purchase a little gain at the cost of Allah's covenant and their oaths . . . Will get painful punishment." (3.77) Ibn Abu `Aufa added, "Such person as described above is a treacherous Riba eater (i.e. eater of usury).
The Prophet (ﷺ) said, "Whoever has to take an oath should swear by Allah or remain silent." (i.e. He should not swear by other than Allah.)