What should a divorced man do whose ex-wife's mother treats him with harshness and estrangement, refusing reconciliation except upon the return of her daughter, knowing that life between them will not continue, despite repeated Istikhara prayers without a breakthrough?

The Sharia (definition) encourages affection and harmony among Muslims, especially relatives, due to the ties of kinship that must be maintained. You have done well in your efforts to please your wife's mother and your eagerness not to sever ties with her. Continue this endeavor and seek help from Allah and those whose advice you trust, for reconciling differences is among the best acts of obedience. Divorce is permissible if there is a need for it, but it is disliked without need, and forbidden by some scholars due to its negative consequences. If you can possibly take your wife back, then do so, especially if she is righteous and you have children together. If you see ill conduct in her, then look at her good qualities, as Allah Almighty says: "And live with them in kindness. For if you dislike them - perhaps you dislike a thing and Allah makes therein much good" (Quran 4:19). And the Prophet, peace and blessings be upon him, said: "A believing man should not hate a believing woman. If he dislikes one of her characteristics, he will be pleased with another." A dream and a feeling of relief are not what one relies on in Istikhara (definition) (prayer for guidance); rather, what counts is the success granted for the completion of the matter for which Istikhara was performed.