Musnad Ahmad 1153:1515

Waki’ narrated to us, from Sufyan, from Mansur, from Ibrahim, from al-Aswad, from ‘Aishah, from the Prophet (peace and blessings of Allah be upon him), who said: "The right of inheritance (al-wala’) belongs to the one who gave the silver (price), and emancipated, and bestowed the favor." And her husband was a free man, so she was given the choice.