Musannaf Ibn Abi Shayba 24:149

Ibn ‘Uyaynah narrated to us, from Ibrahim ibn Maysarah, from Tawus, who said: The rulers were mentioned in the presence of Ibn ‘Abbas, and a man among them spoke harshly regarding them. He stretched himself [in stature] until I did not see anyone in the house taller than him. I heard Ibn ‘Abbas say: "O fool, do not make yourself a trial for the oppressors." So he shrank until I saw him as the shortest among the people.