‘I spoke to her,’ he muttered, after a long silence. ‘I told her she might fool me but she couldn’t fool God. I took her to the window’ – with an effort he got up and walked to the rear window and leaned with his face pressed against it – ‘and I said ‘God knows what you’ve been doing, everything you’ve been doing. You may fool me, but you can’t fool God!’
Standing behind him, Michaelis saw with a shock that he was looking at the eyes of Doctor T. J. Eckleburg, which had just emerged, pale and enormous, from the dissolving night.
‘God sees everything,’ repeated Wilson.
‘That’s an advertisement,’ Michaelis assured him. Something made him turn away from the window and look back into the room. But Wilson stood there a long time, his face close to the window pane, nodding into the twilight.

F. Scott Fitzgerald

The Great Gatsby. Chapter 8, George Wilson is talking about his dead wife Myrtle, whom he found out had been cheating on him. Wilson believes that God, the source of ultimate knowledge and justice, sees everything. He confuses the eyes of Doctor Eckleburg with the eyes of God, but they are the remains of an old billboard advert for a company that no longer exists.