Musnad Ahmad 30:672

'Abd al-Razzaq narrated to us, he said: I heard Hisham ibn Hassan narrating from Muhammad ibn Sirin, he said: I was with Abu Hurayrah, and a man asked him about something—I did not know what it was. He said: So Abu Hurayrah said: "Allah is the Greatest! Two people have asked about this, and this is the third. I heard the Messenger of Allah, peace and blessings of Allah be upon him, say: 'Indeed, there will be men who will be raised by the questioning, until they say: Allah created the creation, so who created Him?'"