It is said that heaven is under the feet of the mother. But in family if the mother always fights and treats her son and daughter-in-law in very bad way and there is no chance of compromise, then (in such case) what are the duties of the husband towards mother and wife?

All perfect praise be to Allah, The Lord of the Worlds. I testify that there is none worthy of worship except Allah, and that Muhammad is His slave and Messenger.

It is completely forbidden to do wrong to your mother in word or in deed. In other words, you have to treat your mother with kindness and to obey her as long as such an obedience does not constitute disobedience to Allah, The Great and Almighty. You have to conform to the Divine Order and the Prophetic precept in this matter.

Allah Says (what means):

• {And We have enjoined upon man, to his parents, good treatment. His mother carried him with hardship and gave birth to him with hardship,…} [Quran 46: 15]

• {And your Lord has decreed that you worship none but Him. And that you be dutiful to your parents. If one of them or both of them attain old age in your life, say not to them a word of disrespect, nor shout at them but address them in terms of honour. And lower unto them the wing of submission and humility through mercy, and say: "My Lord! Bestow on them Your Mercy as they did bring me up when I was small."} [Quran 17: 23-24]

In the same vein, a man came to the Prophet and asked him: “Who is more deserving of my good company?’ The Prophet said: ‘Your mother’. Then, the man said: ‘Then, who?’ The Prophet replied: ‘Then, your mother.’ He said: ‘Then, Who?’ The Prophet again said: ‘Then your mother.’ The man said: ‘Then who?’ Thereupon, the Prophet said: ‘Then, your father’.” [Al-Bukhari and Muslim]

There are many other verses and Ahadeeth that urge Muslims to be dutiful to their parents, especially the mother.

Therefore, it is your duty to advise your mother in a soft and gentle manner and to draw her attention to the fact that she has to fear Allah and not to wrong your wife as well as to state the bad consequences of injustice in this worldly life and Hereafter.

In addition, you have to advise your wife to be patient, to control herself and to do her best to be good with your mother.

Allah Says (what means): {And not equal are the good deed and the bad. Repel [evil] by that [deed] which is better; and thereupon the one whom between you and him is enmity [will become] as though he was a devoted friend. But none is granted it except those who are patient, and none is granted it except one having a great portion [of good].} [Quran 41: 34-35]

Then, if your problem is solved, Allah willing, then this is what is required. Otherwise, it is your duty to do your best to prevent your wife from coming in close contact with your mother even if it becomes necessary to move to live in another house if your mother accepts such a step. Then, if something bad takes place in your presence, you have to cool her down and busy her in something else.

Furthermore, it is known that some wives pretend to be wronged, but in fact they are unjust and they do so to make the husband undutiful to his parents. This, for sure, leads the husband to destruction, since Allah joins ordering to be kind with parents and prohibition of Shirk (polytheism). He Says (what means): {[He commands] that you not associate anything with Him, and to parents, good treatment, …} [Quran 6:151]

This means that one has to guard his parents' rights to filial duty.

Allah knows best.