What is the ruling of the Sharia on a husband's mother asking her son to buy her gold, and what are the limits of a husband's financial support for his mother, knowing that the couple is still building their life?

The husband is not obligated to financially support his mother unless two conditions are met: that she is poor, and that the money is in excess of his needs and the needs of his wife and children. The obligatory support for the mother includes her necessities and essential needs such as food, drink, housing, medical treatment, and clothing, but it does not include improvements or luxuries.