Does the waiting period for a divorced woman intending to marry another man begin from the date of separation or from the date of the court's ruling, and what is the ruling on her marrying customarily before the waiting period ends and documenting it later, and what is the ruling on one who issued a fatwa validating this marriage, and what is the expiation for an incorrect fatwa?

The 'iddah (waiting period) of a woman begins from the date of the ruling of her divorce. It is not permissible for her to marry until it has concluded, based on the Almighty's saying: "And do not determine to consummate the marriage contract until the prescribed period reaches its end." (Quran 2:235). It is not permissible to propose to her while she is in her 'iddah. If the marriage contract was concluded during the 'iddah without consummation until it ended, the preponderant opinion is that she is not forbidden to him. However, if consummation occurred, many scholars believe that she becomes permanently forbidden to him, while the Shafi'is and Hanafis hold that it is permissible for her to marry him with a new contract. The aforementioned marriage is void because she was still in her 'iddah. If the second husband was aware of this, then they both committed a great sin, but she is not forbidden to him unless he consummated the marriage with her. She must complete the 'iddah from the first husband and then commence another 'iddah from the second.