What is the ruling regarding the husband's divorce taking effect if he swore to divorce me while he was in full possession of his mental faculties, bearing in mind that there was a previous divorce from which he returned by means of expiation?

The majority of jurists hold that divorce occurs if one who swore an oath by divorce breaks it. Therefore, the mentioned divorce takes place. Since the husband had divorced once before, he has the right to take his wife back as long as her waiting period ('iddah) has not ended, and he can do so even if she objects, and no expiation is required of him. It should be noted that swearing an oath by divorce is not permissible, according to the saying of the Prophet, peace and blessings be upon him: "Whoever takes an oath, let him swear by Allah or remain silent." A Muslim should not accustom his tongue to oaths of divorce or other impermissible oaths. If the spouses and their families are unable to resolve marital problems, they should refer them to the Sharia courts.