Musannaf Ibn Abi Shayba 33:373

Abu Usama narrated to us, from Sulayman ibn al-Mughira, from Humayd ibn Hilal, who said: Abu al-Darda’ said: "The thing I fear most, when I stand for the reckoning, is that it will be said to me: 'You have known, so what did you do regarding what you knew?'"