Al-Hasan (may Allah have mercy on him) said concerning the saying of Allah Almighty, "Do not prevent them from marrying their husbands" [Surah al-Baqarah: 232]: Ma'qil bin Yasar (may Allah be pleased with him) narrated to me that this verse was revealed concerning him. (He said:) I married my sister to a man. He divorced her, until her waiting period ended. Then he came and proposed marriage to her again. I said to him: I married her to you, provided you with a bed and honoured you, and you divorced her; then you come proposing to her. By Allah! I will never marry her to you. He was a man in whom there was no harm, and the woman wanted to return to her husband, so Allah Almighty revealed this verse: "And when you divorce women and they reach the end of their waiting period, do not prevent them" [Surah al-Baqarah: 232]. So I said: O Prophet of Allah (peace and blessings be upon him)! Now I will marry her (to him), and I married her (to him).
Hadith Referenceالسنن الكبرى للبيهقي / كتاب النكاح / 13594