Musannaf Ibn Abi Shayba 3:5182

Abu Bakr narrated to us, he said: Isa ibn Yunus narrated to us, from al-Awza’i, from Umayr ibn Hani, he said: I witnessed Ibn Umar while al-Hajjaj was besieging Ibn al-Zubayr. The residence of Ibn Umar was between them. Sometimes he would attend the prayer with these, and sometimes he would attend the prayer with those.