If the lamp turned upside down, it would go out in the course of nature. Any oil lamp would.
8 seconds sound clip from the The Man Who Could Work Miracles (1954) movie soundboard.
You can hear this line at 00:03:38 in the DVD version of the movie.
Quote context
[...]
- Well no, not so far as it goes.
- Very well. Now let's take a common instance.
- Well, now let me show you what I mean by a miracle.
- That oil lamp, in the course of nature, couldn't turn upside down and keep on burning, could it?
- Well, could it? Never mind what I say, what do you say?
- If the lamp turned upside down, it would go out in the course of nature. Any oil lamp would.
- I can't keep it up, my willpower, any longer.
- This is a respectable house, and we don't want anything like that in it. Conjuring tricks.
[...]