In Nahj al-Balaghah, it is related that Imam 'Ali said, "A woman's jealousy is disbelief, and a man's jealousy is faith."
This is generally explained by saying that a woman should not be jealous of her husband for lawfully taking another woman (such as a co-wife), because it is allowed. However, a man's jealousy over his woman will impel him to protect her from other men.
(Sadly, many customs and traditions worldwide regarding women boil down to protecting women from overeager men!)
Either this attribution to Imam Ali is accurate; or, possibly, there is a cultural element to this attribution to Imam 'Ali since many cultures have this sense of machismo.
Al-Kafi also contains a hadith which says that a woman's ghirah stems from love (al-Kāfī, vol. 5, p. 506, no. 6). That is, because she loves her husband, she wants him for herself.
Some narrations discuss ghirah relating to Allah; for instance, because of his ghirah, Allah hates the forbidden things. This is somewhat similar to the idea of sexual morality (just as the womenfolk are described as the haram and off limits to other men, the sins are described as haraam and off limits to people) but is also broader. It seems to be the Islamic way that the Old Testament idea of a "jealous God" is revised.
