In verse 2:235 of the Holy Quran, Allah (swt) says,
‘And there is no blame on you respecting that which you speak indirectly in the asking of (such) women in marriage or keep (the proposal) concealed within your minds; Allah knows that you win mention them, but do not give them a proposal in secret unless you speak in a lawful manner, and do not consummate the marriage tie unless the writing is fulfilled, and know that Allah knows what is in your minds, therefore beware of Him and know that Allah is forgiving and Bearing.”
This verse has laid down the Islamic law on proposing a widow or a divorcee. If a man desires to marry a widow or a divorcee, he is supposed to give them an indirect hint only regarding his wish. For example, the man may tell a woman that he desires to get married to a virtuous woman.
The men are not permitted to take a pledge of marriage from such women, stealthily. They are also not allowed to marry such woman before the completion of the waiting period/iddat.
On the contrary, the men are not allowed to give even the slightest hint, about their desire to marry, to the women who have been given talaq-ar-raji or a revocable divorce. This is because the husband of such a woman still retains the rights over her till he pronounces divorce three times, i.e. he gives her an irrevocable divorce/ talaq-e- bain. Otherwise there are ample chances of reconciliation between the husband and wife. Therefore it is unlawful for a man to propose such women (who still have chances of being taken back by their husbands) even indirectly.
Keep Me In Your Prayers.