1,811. When the First Husband Turns Up Alive
Hilchos Geirushin 10:6
If, after a woman was betrothed, her first husband turns up alive or it is discovered that her get is invalid, she is still permitted to the first husband. She need not be divorced by the second husband because marriage cannot be effected with a woman who is one of the prohibited relationships. We’re not concerned in this case that people might think that a married woman was released without a get. Since the second marriage was never finalized, people will assume that the betrothal was based on a condition that was never met.
Hilchos Geirushin 10:7
Let’s say that a woman remarried and it was subsequently found that her get was invalid or her first husband turned up alive. Neither the first nor the second husband can claim rights to ownerless objects that the woman finds or to the proceeds of her work, nor can they annul her vows. None of the benefits that either of them received after she remarried should be taken away. Neither of them is obligated to pay her the value of her kesubah, nor to meet any of its conditions. Neither is required to pay for her maintenance; if she took money from either of them for maintenance, she must return it. Neither of them is responsible for property that she brought into the marriage that was lost or got worn out, not even for “iron sheep property.” (See halacha 16:1 for an explanation of "iron sheep property." Any children produced by the second marriage are illegitimate; if the first husband is intimate with her before she is divorced by the second husband, the resulting child is illegitimate under rabbinic law. If the second man divorces her and she is paid the value of her kesubah, only after which the first husband turns up alive or her divorce is found to be invalid, we do not take away the money she received for maintenance or as payment for her kesubah.