Musnad Ahmad 284:5

Ya'qub ibn Ibrahim narrated to us, he said: My father narrated to us, from Ibn Ishaq, he said: My father, Ishaq ibn Yasar, narrated to me, he said: We were in Makkah when Abdullah ibn al-Zubayr came out to us and forbade the *Tamattu'* (combining) of the 'Umrah with the Hajj, and he denied that the people had done that with the Messenger of Allah, may Allah bless him and grant him peace. This reached Abdullah ibn Abbas, so he said: "What does Ibn al-Zubayr know about this? Let him return to his mother, Asma bint Abi Bakr, and ask her. If al-Zubayr had not returned to her as a *halal* (having exited the state of Ihram) and she became *halal* (for him)?" This reached Asma, so she said: "May Allah forgive Ibn Abbas; by Allah, he has spoken obscenely. By Allah, Ibn Abbas has spoken the truth: 'They became *halal* (exited Ihram), and we became *halal*, and they had relations with women.'"