What is the reason for the change in the mother's treatment of her eldest son after his marriage, and her insulting and cursing him in front of his wife and siblings, even though he does not fall short in his duties towards her, and despite his inability to live separately due to his financial circumstances?

What you are experiencing may be due to your mother's feeling of jealousy or of losing you after marriage. To solve this problem, you should:

1. Strive to be kind to her and make her feel your attention.

2. Avoid praising your wife in front of her, while still giving your wife her due honor away from your mother.

3. Encourage your wife to draw closer to your mother.

4. Be patient with any ill-treatment that may come from her, in accordance with the Almighty's saying: (Repel [evil] with that which is better, and thereupon the one whom between you and him is enmity [will become] as though he was a devoted friend).

5. Supplicate for her success and guidance.

6. Be a good example to your siblings in patience, kindness, and dutifulness, and remember the Almighty's saying: (So do not say to them [anything that indicates] displeasure and do not scold them but speak to them a noble word).

7. Discuss the problem with one of your siblings to understand any hidden reasons.