Musnad Ahmad 289:5

Yazid ibn Harun narrated to us, he said: Hammad ibn Salamah informed us, from Ya'la ibn 'Ata, from Waki' ibn Hudus, from his paternal uncle Abu Razin, who said: I said: "O Messenger of Allah, will every one of us see Allah, the Mighty and Majestic, on the Day of Resurrection? And what is the sign of that in His creation?" He said: "O Abu Razin, does not every one of you see the moon while being alone with it?" I said: "Yes, O Messenger of Allah." He said: "Then Allah is greater."