Does divorce occur in the three aforementioned cases, knowing that it was intended as a threat, and with the expiation of an oath? What is the religious ruling on tearing up the marriage certificate? And what is the status of the previous marriage after tearing up the document and the impending official marriage?

Of common-law marriages, some are valid and some are void. If the aforementioned marriage is valid, its effects—including those related to divorce—will ensue.

If the uttered phrase is an explicit divorce pronouncement, such as "You are divorced," then divorce occurs regardless of intention. However, if it is an allusion (kinayah) to divorce, such as "Go join your family," then divorce does not occur unless accompanied by the intention to divorce.

If it is an oath of divorce or a conditional divorce, then there is a detailed explanation for that. A wife tearing up the marriage certificate does not affect the marriage.