That is the legend of Ananka.
2 seconds sound clip from the The Mummy (1959) movie soundboard.
You can hear this line at 00:46:33.520 in the Blu-ray version of the movie.
Quote context
[...]
- Death was not for Kharis, nor was life.
- For his sins, he was sentenced to remain for all time on guard near the body of his princess.
- He was buried alive in a secret tomb specially prepared for him.
- The rest of them never got back to Egypt. Illness perhaps? Savages? Who knows.
- That is the legend of Ananka.
- The dictionary defines legend as being historical myth.
- But don't forget half the story we know is fact.
- We know that Ananka died on a pilgrimage and was buried somewhere in the jungle.
- We know that no survivors ever returned to Egypt.
- Now, if half the story is true, why not the other half?
- Because the other half is removed from fact. It's fantasy.
[...]