Mughirah (may Allah have mercy on him) narrated from al-Sha'bi (may Allah have mercy on him): A man from among us married a woman and divorced her before consummating the marriage, and the woman's brother forgave her dowry. The matter was taken to Qadi Shurayh (may Allah have mercy on him), and he declared the forgiving of the dowry valid. Then he said: "I would then forgive the dowry of my children at once." After that he used to say: "The one in whose hand is the marriage tie [Surah al-Baqarah: 237] is the husband: either he hands the full dowry over to the wife, or the woman forgoes the half that Allah Almighty has fixed for her; and if they dispute, the woman receives half the dowry."
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الصداق / 14451