2:235Al-Baqara

You would not be at fault regarding the proposal with the intention of marriage you present offer or hide in your hearts during the waiting period to women whose spouses have died such as men saying ‘How beautiful you are!’ or ‘Who could find one like you?’ or ‘How many a man must desire you!’. God knows that you will be mindful of them in proposing to them impatiently and so He has permitted you to make such offers; but do not make arrangements of marriage with them secretly unless you speak honourable words such as are acknowledged by the Law in other words such as proposals that which is permitted to you. And do not resolve on the knot the consummation of marriage until that which is written the period prescribed has reached its term and has been completed; and know that God knows what is in your souls of resolve or otherwise; so be fearful of Him that He should chastise you if you have made such resolve; and know that God is Forgiving toward him who is fearful of Him Forbearing in delaying the chastisement of the one deserving it.