Sahih Bukhari
Punishment of Disbelievers at War with Allah and His Apostle
Volume: 008 / Book Number: 082 / Hadith Number: 829
Narrated Al-Mughira:
Sa'd bin Ubada said, "If I found a man with my wife, I would kill him with the sharp side of my sword." When the Prophet heard that he said, "Do you wonder at Sa'd's sense of ghira (self-respect)? Verily, I have more sense of ghira than Sa'd, and Allah has more sense of ghira than I."