Musannaf Ibn Abi Shayba 24:179

Mu'adh ibn Mu'adh narrated to us, from Abu Ma'dan, from Malik ibn Dinar, who said: I witnessed al-Hasan, Malik ibn Dinar, Muslim ibn Yasar, and Sa'd commanding [the people] to fight al-Hajjaj alongside Ibn al-Ash'ath. Al-Hasan said: "Indeed, al-Hajjaj is a punishment that has come from the heaven, so do not meet the punishment of Allah with the sword."