Harming the daughter-in-law is an injustice and manifest sin
15-1-2014 | IslamWeb
Question:
What is the Sharee‘ah ruling on the mother who treats her daughter-in-law badly and plans to make her life miserable. That woman does not feel shame to falsely accuse her daughter-in-law of any accusation. She does so to get her son’s love for herself only. What should the son do when his mother asks him to punish his guiltless wife?
Answer:
All perfect praise be to Allaah, The Lord of the Worlds. I testify that there is none worthy of worship except Allaah, and that Muhammad, sallallaahu ‘alayhi wa sallam, is His Slave and Messenger.
Undoubtedly, harming Muslims is one of the most detestable and prohibited matters in Islam. There are many Quranic and Prophetic texts that prohibit this and stress the relevant severe threat. In the Quran, Allaah The Almighty Says (what mean): {And those who harm believing men and believing women for [something] other than what they have earned have certainly born upon themselves a slander and manifest sin.} [Quran 33: 58]
In an authentic Hadeeth, the Prophet, sallallaahu ‘alayhi wa sallam, said: "Insulting a Muslim is a wrongdoing and fighting him is disbelief". [Muslim]
Abu Hurayrah 
narrated that the Prophet, sallallaahu ‘alayhi wa sallam, said: "Do not envy one another; do not inflate prices for one another; do not hate one another; do not turn your back on one another (in discontent) and do not bid against one another (but) be slaves of Allaah as brothers. The Muslim is the brother of the Muslim. He neither oppresses him nor humiliates him nor looks down upon him. Piety is here – and he pointed to his chest three times. It is evil enough for a Muslim to hold his Muslim brother in contempt. All of the Muslim is inviolable for the Muslim: his blood, his property and his honor." [Muslim]
Consequently, if what you said about your mother-in-law is right, she will be required to repent to Allaah The Almighty and refrain from creating dissention between you and your husband. As such, she incurs another sin which is incitement. The Prophet, sallallaahu ‘alayhi wa sallam, said: “Anyone who incites a woman against her husband or a slave against his master is not one of us.” [Abu Daawood]
By the way, we advise you to be patient, treat that woman kindly and meet her actions with good morals and forgiveness. If you kept straight on this, undoubtedly, her treatment would be changed to the best.
Your husband, on the other hand, should try to reconcile between you and his mother and settle all these problems. He is not permitted to obey his mother if she asked him to do something with you which is against the Sharee‘ah, whether it is an action or a saying. A creature should not be obeyed at the expense of disobeying the Creator.
We draw attention to the fact that if living in an independent house will settle this problem, you as well as your husband should seek this in order to avoid problems with your mother-in-law.
Allaah Knows best.