Musnad Ahmad 1153:1891

Muhammad ibn Salamah narrated to us, from Ibn Ishaq, from Aban ibn Salih, from al-Hasan ibn Muslim ibn Yanaq, from Safiyyah bint Shaybah, from Aisha, who said: A woman came to her and said: "My daughter has lost her hair; shall we put something on her head to beautify her with it?" She said: "I heard a woman asking the Messenger of Allah (peace and blessings of Allah be upon him) about the same thing you asked about, and he said: 'Allah has cursed the woman who adds hair extensions and the one who asks for them to be added.'"