Musnad Ahmad 25:152

Yahya narrated to us, from Ibn Jurayj, Al-Hasan ibn Muslim narrated to me, from Tawus, who said: I was with Ibn Abbas, and Zayd ibn Thabit said to him: "Do you issue a fatwa that a menstruating woman may depart [from Makkah] before her last act [of worship] is at the House [the Ka'bah]?" He said: "Yes." He said: "Then do not issue that fatwa." He said: "If you insist, then ask such-and-such Ansari woman: Did the Prophet, peace and blessings of Allah be upon him, command her to do that?" Zayd returned to Ibn Abbas laughing, and said: "I see that you have indeed spoken the truth."