If you divorced women, after their Iddah do not prevent them from remarrying their husbands whom they like. This is an advice from Allah, to those who believe Allah and the Last Day. It is holy and pure. Allah knows and you do not.
(Al-Quran 2:232)
If your wives live after your death and they want to remarry, they should wait four months and ten days. When they fulfilled their term, there is no blame on you if they choose their way of life in a just and reasonable manner. Allah knows well what you do.
(Al-Quran 2:234)
(During this Iddah period,) if you wish to marry them or talk suggestively about marrying them, you will not be blamed. Say good words. But do not promise. Do not decide to marry till the ordained time elapses. Allah knows that you wish to marry them. So fear Allah. He is forgiving and tolerant.
(Al-Quran 2:235)