Musnad Ahmad 1153:1902

Abu Mu'awiyah narrated to us, Hisham ibn 'Urwah narrated to us, from his father, from 'Aishah, who said: A man divorced his wife, so she married a husband other than him. He entered upon her, and he had with him something like the fringe of a garment, and he did not approach her except for one single approach, and he did not reach anything from her. She mentioned that to the Prophet, may Allah bless him and grant him peace, and she said: "Am I permitted for my first husband?" The Messenger of Allah, may Allah bless him and grant him peace, said: "You are not permitted for your first husband until the other tastes your sweetness and you taste his sweetness."