Musnad Ahmad 1172:1

Muhammad ibn Ja'far narrated to us, he said: Shu'bah narrated to us, from Muhammad ibn al-Nu'man, he said: I heard Talhah al-Iyami narrating, and Yahya ibn Sa'id [narrated] from Shu'bah, he said: Muhammad ibn al-Nu'man informed me, from Talhah ibn Musarrif, from a woman from Banu 'Abd al-Qays, from the sister of 'Abd Allah ibn Rawahah al-Ansari, from the Messenger of Allah, peace and blessings of Allah be upon him, that he said: "Going out [for the two Eids] is obligatory upon every woman who wears a waist-wrapper."