Musnad Ahmad 1167:68

Yahya ibn Sa'id narrated to us, from Hisham, who said: Fatimah bint al-Mundhir narrated to me, from Asma' bint Abi Bakr, that a woman from the Ansar said to the Messenger of Allah (may Allah bless him and grant him peace): "I have a young daughter who is a bride, and her hair has fallen out. Is there any sin upon me if I attach hair to her head?" And Waki' said: "Her hair has thinned out." He said: "Allah has cursed the woman who attaches hair and the one who has it attached."