Musannaf Ibn Abi Shayba 7:81

Abu Abd al-Rahman al-Muqri narrated to us, he said: Sa'id ibn Abi Ayyub narrated to us, he said: Yazid ibn Abi Habib narrated to us, from Ibn Shihab, from Ibn al-Musayyib, who said: As for the woman, she fasts, and when she menstruates, she completes what remains.