What should a son do to resolve the conflict between his mother and wife, who cannot stand living together, given his desire to please both parties and preserve family cohesion amidst difficult financial circumstances?

The mother's right is immense, and showing devotion to her is one of the best acts of worship. However, devotion to her is not limited to housing her in your home. If she is living with your brother and is not suffering any harm, then you are not required to move her. You can show devotion to her by visiting her, inquiring about her well-being, obeying her in what is right, being benevolent to her financially, fulfilling her needs, and speaking kindly to her.

Know that it is your wife's right that you provide her with a suitable independent home where she will not be exposed to harm, and she is not obligated to accept living with your mother.

Your duty is to combine devotion to your mother with good companionship to your wife, and to give everyone their due rights.