What is the ruling regarding a woman who withholds intercourse from her husband due to her sadness with him?

The husband's right over his wife is great, and this includes obeying him in responding to his call to bed, unless she has a legitimate excuse such as illness, menstruation, obligatory fasting, or harm. A severe warning has been reported for those who refuse without an excuse. The Prophet, peace and blessings be upon him, said: "If a man calls his wife to his bed and she refuses to come, the angels curse her until the morning." Therefore, it is not permissible for a woman to refuse merely due to sadness or unwillingness; rather, she must obey him whenever he calls her and she is able.