Musnad Abu Ya'la al-Mawsili 214:5

Zuhayr narrated to us, Ya'qub ibn Ibrahim narrated to us, he said: My father narrated to me, from Ibn Ishaq, he said: Husayn ibn 'Abd Allah informed me, from 'Ikrimah, from Ibn 'Abbas, from Umm al-Fadl bint al-Harith, that the Messenger of Allah (may Allah bless him and grant him peace) saw Umm Habibah while she was a little above the age of weaning. He said: "If this daughter of al-'Abbas reaches [adulthood] while I am alive, I will surely marry her."