Abdur Rahman bin Qasim narrates from his father that regarding the command of Allah Almighty: "There is no sin upon you if you hint at a proposal of marriage to women" (Al-Baqarah: 235), he says: Its meaning is that a man may say to a woman during her waiting period after her husband's death: "You are honorable to me, I am inclined towards you, Allah Almighty will bring goodness or sustenance to you," or he may say something similar to this.
Hadith Referenceمسند الإمام الشافعي / كتاب النكاح / 1130
Hadith Takhrijصحيح اخرجه البيهقى 178/7 - وابن ابى شيبة (16835) ، (16844) - ومالك في الموطا، النكاح، باب ماجاء في الخطبة۔