2/Al-Baqarah-234: The wives of those who are made to die and leave them behind, should keep themselves in waiting for four months and ten days; then when they have fully attained their term, there is no sin on you for what they do for themselves in a lawful manner (on a reasonable basis, bi’l ma’rûf) and Allah is Well-Acquainted with what you do.
2/Al-Baqarah-235: And there is no sin on you if you make a hint of betrothal (to the women who are in the waiting-period) or conceal such a desire in yourself. Allah knows that you will remember them, but do not give them a promise in secret except (a hint of betrothal) that you speak in a lawful manner (according to usage, on a reasonable basis). Do not resolve on the tie of marriage before the end of their waiting-period. And know that Allah knows what is in you, therefore beware of Him. And know that Allah is Oft-Forgiving, Most Gentle.
2/Al-Baqarah-236: There is no sin on you if you divorce the women while yet you have not touched them, nor appointed unto them their “Mahr” (bridal-money). Provide for them with fairness (according to custom and usage) the wealthy according to his means and the straitened according to his means: This is a binding duty upon the Muhsinûn.
2/Al-Baqarah-237: If you divorce them before you have touched them and you have appointed for them the Mahr (bridal-money) then paying half of what you have appointed is upon you, unless they (the women) relinquish (it) or (the whole amount) is remitted by him in whose hand is the marriage tie (the bridegroom). And to forgo and give (the other half as well) is nearer to Takwâ (having piety). And do not forget the Merit between you. Truly, Allah is All-Seeing of what you do.