Bukhari :: Book 3 :: Volume 48 :: Hadith 820
The Prophet 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."
Source materials are from the University of Southern California MSA site|
Hadith eBooks converted from Imaan Star