Musannaf Ibn Abi Shayba 33:1173

Mu'adh ibn Mu'adh narrated to us, from Ibn 'Awn, who said: Ibrahim mentioned that Al-Mukhtar ibn Abi 'Ubayd sent for him. He said: So he (Ibrahim) smeared his face with a coating and drank medicine, and he did not come to them, so they left him.