What is the ruling of Islamic law regarding a husband remaining with his obedient wife, who faces abuse and threats of expulsion and humiliation from his mother, who demands that he divorce her, and what is his stance regarding honoring his mother and pleasing his wife?

The wife has done well by patiently enduring her mother-in-law's harm. The husband should continue to advise his mother in a kind manner, seek help from those whose advice he hopes will be beneficial, and pray for her guidance. It is not necessary to divorce a righteous wife based on the mother's desire. The wife has the right to an independent dwelling where she is safe from harm, and this takes precedence over settling debts because it is part of the obligatory maintenance. One must be dutiful and kind to the mother, even if she acts poorly.