Sahih Bukhari, Chapter: Wills and Testaments (Wasaya)

"A man from the tribe of Bani Sahm went out in the company of Tamim Ad-Dari and Adi bin Badda. The man of Bani Sahm died in a land where there was no Muslim. When Tamim and Adi returned conveying the property of the deceased, they claimed that they had lost a silver bowl with gold engraving. Allah's Messenger made them take an oath (to confirm their claim), and then the bowl was found in Makkah with some people who claimed that they had bought it from Tamim and Adi. Then two witnesses from the relatives of the deceased got up and swore that their witnesses were more valid than the witnesses of Tamim and Adi, and that the bowl belonged to their deceased fellow. So, this Verse was revealed in connection with this case; 'O you who believe! When death approaches any of you....' " (5.106)