Musnad Ahmad 1153:788

Husayn narrated to us, he said: Shu'bah ibn al-Hajjaj al-'Ataki narrated to us, from 'Amr ibn Murrah, he said: I heard al-Hasan ibn Muslim ibn Yanaq narrating from Safiyyah bint Shaybah, from 'Aishah, that a young woman from the Ansar was married, and she became ill, so her hair fell out. They wanted to add hair to it, so they asked the Messenger of Allah, peace and blessings of Allah be upon him, about adding hair. He cursed the one who adds hair and the one who asks for it to be added.