Musnad Ahmad 1153:1233

Muhammad ibn Bishr narrated to us, Hisham ibn Urwah narrated to us, from his father, from Aisha: That she used to reproach the women who offered themselves to the Messenger of Allah (peace and blessings of Allah be upon him). She said: "Does a woman not feel ashamed to offer herself without a dowry?" Then it was revealed, or she said: Allah the Almighty and Majestic revealed: {You may postpone whom you will of them and take to yourself whom you will} [Al-Ahzab: 51], and whomsoever you desire of those you have set aside, there is no blame upon you. She said: "I see that your Lord, the Almighty and Majestic, hastens to fulfill your desires."