Is it permissible to visit one's mother and sit with her on the stairs outside her apartment after the husband swore by divorce that she should not visit her mother, knowing that the wife visits the husband's mother?

It is not permissible for a husband to prevent his wife from maintaining obligatory ties of kinship, such as with her mother. The preponderant opinion is that she is not obligated to obey him in this matter. If the husband swears an oath of divorce that his wife will not visit her mother, then if his intention was to prevent visitation in her home, the oath is not broken by a visit outside her home. However, if he intended to prevent visitation absolutely, then the oath is broken by any visit whatsoever. The majority of scholars hold that divorce occurs upon breaking the oath, whereas Sheikh al-Islam Ibn Taymiyyah is of the view that in this case, an oath of divorce necessitates expiation for a broken oath. If a divorce occurs, the husband may reconcile with his wife before the expiry of her iddah (definition) if it was the first or second divorce.