Sahih Muslim Book 009, Hadith Number 3572.
Chapter: Li'an (Invoking curse).
AI-Mughira b. Shu'ba (Allah be pleased with him) reported that Sa'd b. 'Ubada (Allah be pleased with him) said: If I were to see a man with my wife, I would have struck him with the sword, and not with the flat part (side) of it. When Allah's Messenger (may peace be upon him) heard of that, he said: Are you surprised at Sa'd's jealousy of his honour? By Allah, I am more jealous of my honour than he, and Allah is more jealous than I. Because of His jealousy Allah has prohibited abomination, both open and secret And no person is more jealous of his honour than Allah, and no persons, is more fond of accepting an excuse than Allah, on account of which He has sent messengers, announcers of glad tidings and warners; and no one is more fond of praise than Allah on account of which Allah has promised Paradise.