Musnad Ahmad 1017:119

Waki’ narrated to us, Sufyan narrated to us, from ‘Abdullah ibn ‘Ata’, from ‘Abdullah ibn Buraydah, from his father, who said: A woman came to the Prophet, may Allah bless him and grant him peace, and said: "I gave a slave girl as charity to my mother, and she has died." He said: "May Allah reward you, and the inheritance has returned to you."