What is the ruling of Islamic law regarding the forcible separation of a married couple, and what advice should be given to whoever does so?

If the legitimate marriage contract was concluded in the presence of the guardian and witnesses, then the wife has become legitimate, and the written contract is not a condition for its validity. Forcing the wife's father to divorce is forbidden instigation (takhbib) and a grave sin. Psychological pressure is not a compelling duress that prevents the occurrence of divorce; rather, religiously recognized duress involves threats or harm to oneself or property. If a divorce occurs, it is possible to seek a way for a new contract through the mediation of some virtuous individuals to convince the father. If the wife has had a valid seclusion (khalwa sahiha) with her husband, she is obligated to observe the waiting period ('iddah), and the husband has the right to take her back as long as she is within the 'iddah without a new contract. If the 'iddah ends, a new contract must be renewed.