In Islam, marriage is a sacred bond that cannot be easily broken. Thus, Islam has prescribed a long process for separation between spouses in order to give chance to the reunion of the family and the perpetuation of the relation.
In case divorce has taken effect, a divorced woman still has to wait for a fixed period of time during which it is impermissible for any other man to propose to her for marriage.
Dr. Salah Al-Sawy said:
According to the consensus of Muslim jurists (Ijma`), a woman who has been given a revocable divorce and is still in her waiting period (`iddah) is prohibited to be proposed to, either overtly or by allusion.
So, how about a woman who is still married to her husband and is still under his authority? It is not permissible for her as a married woman to ever speak to any man about a future marriage, whether the discussion is overt or allusive, until the divorce has come to pass and she has become completely free of all the consequences of the first marriage by completing the waiting period.