Abd al-Rahman bin al-Qasim (may Allah have mercy on him) narrates from his father (may Allah have mercy on him) that he said regarding the words of Allah, "And there is no sin upon you in what you hint of a proposal of marriage to women" [Surah al-Baqarah: 235]: It is that a man says to a woman who is observing the waiting period after her husband's death: "You are honoured in my eyes, I am desirous of you, and Allah will bring good and provision to you," saying things of this kind.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب النكاح / 14020