Sahih al-Bukhari Book 48, Hadith 8
Abdullah (bin Mas'ud) said, "Whoever took a false oath in order to grab somebody's property will meet Allah while Allah will be angry with him." Allah revealed the following verse to confirm that:--"Verily! Those who purchase a small gain at the cost of Allah's covenant And their oaths...a painful torment." (3.77) Al-Ash'ath bin Qais came to us and asked as to what Abu Abdur-Rehman (i.e. Ibn Mas'ud) was telling you." We related the story to him. On that he said, "He has told the truth. This verse was revealed about me. I had some dispute with another man regarding a well and we took the case before Allah's Messenger (ﷺ). Allah's Messenger (ﷺ) said (to me), "Produce two witnesses (to support your claim); otherwise the defendant has the right to take an oath (to refute your claim).' I said, 'The defendant would not mind to take a false oath." Allah's Messenger (ﷺ) then said, 'Whoever took a false oath in order to grab someone else's property will meet Allah, Allah will be angry with him.' Allah then revealed what Confirmed it." Al-Ash'ath then recited the following Verse:--"Verily! Those who purchase a small gain at the cost of Allah's covenant, And their oaths . . . (to) . . . they shall have a painful torment!' (3.77) (See Hadith No. 546)
I wrote a letter to Ibn `Abbas and he wrote to me that the Prophet (ﷺ) had given the verdict that the defendant had to take an oath.
The Prophet (ﷺ) said, "Whoever frees a Muslim slave, Allah will save all the parts of his body from the (Hell) Fire as he has freed the body-parts of the slave." Sa`id bin Marjana said that he narrated that Hadith to `Ali bin Al-Husain and he freed his slave for whom `Abdullah bin Ja`far had offered him ten thousand Dirhams or one-thousand Dinars.