What is the ruling on a husband who does not provide for his wife, using his mother's medical treatment as an excuse, and wants to send his mother abroad for recreational treatment, while his wife needs money for the household and her child?

A husband must spend on his wife reasonably. If he does so, he may spend on his mother as he wishes. The obligatory expenditure for the wife is what is sufficient for food, housing, and clothing, in a reasonable manner. If spending on the wife and child conflicts with spending on the mother, then the wife's expenditure takes precedence over all others. The wife can remind her husband of this, or involve sensible people as mediators. If that does not work, she may refer the matter to the judiciary to compel him to provide maintenance.