The husband himself may be the cause of an unhappy marriage. For example, he may be very stingy and miserly… He may also be someone who is very harsh, tough and despotic. He may be one who forces his will and decisions upon his wife in every matter without consulting with her, taking into consideration her feelings, exchanging views on the matter and being pleasant with this wife.
He might consider his wife like some kind of chattel [instead of another human] and therefore deals with her with coldness and coarseness without any compassion or gentleness…
“He may cause his wife different forms of harm, such as cursing her or her family, reviling her, verbally abusing her for the tiniest of reasons… Or [another act of nushooz on his part is that] he may try to bring harm to her by divorcing her and then, before the waiting period is finished, bring her back as his wife and then divorce her again. All this is done without the intention of returning to a real married life but simply to harm her and transgress her rights. Or he may avoid having sexual intercourse with her for no reason or legal sanction. This may lead the woman to lose her chastity and doing something forbidden.” [Al-Bahuti al-Hanbali, Kishaaf al-Qinaa’ an Matn al-Iqnaa’, vol. 5, pp. 184, 290, 213; Ibn Abideen, Radd al-Mukhtar ala al-Darr al-Mukhtar wa Hashiyah, vol. 3, p. 190; Tafseer al-Manaar, vol. 5, p. 76.]
Shaikh al-Islam ibn Taimiyyah stated,
“The harm that comes about to the woman by the man avoiding sexual intercourse with her is such that the marriage may be dissolved under every circumstance, regardless if it was intentional from the husband or unintentional, or if he had the ability to perform sexual intercourse or not.”
[Ibn Taimiyah, al-Fatawa al-Kubra, vol. 4, p. 562; Ibn Taimiyah, Majmuah al-Fatawa, vol. 32, p. 40.]
[Nushooz on the part of the husband includes] when he orders her to do something forbidden or illegal, such as going out in public displaying her beauty or uncovering parts of her that must be covered, to go among men she is not related to…
Or, he may not fulfil the needs of his wife and children such that their well-being is not met. Or, he does things that hurt and dishonor his wife and show lack of respect for her, such as backbiting her, slandering her or joking about her. Or, he may be desirous of her wealth and forces her to spend it on his behalf.
[Taken From “Marital Discord (An-Nushooz)” by Sh. Saalih Al-Sadlaan, p. 32]