What is the ruling if a man marries a polytheist woman, she converts before him, and then he marries her sister while in a state of disbelief, and they all convert within the waiting period (*iddah*) of the first wife?

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He has the right to choose between the two sisters because he converted while married to two sisters who are now Muslim. If he converted first, he is not permitted to marry her sister within her *iddah*, nor marry four others besides her. If he did so, the second marriage is invalid. If the first wife converts during her *iddah*, her marriage is binding because she is now exclusively his.