The day you break that oath will be the last your eyes shall ever see.

4 seconds sound clip from the The Ten Commandments (1956) movie soundboard.

You can hear this line at 00:16:54.605 in the Blu-ray version of the movie.

Quote context

[...]

- My mother and her mother before her were branded to the Pharaoh's service.

- I will not see you make this son of slaves a prince of Egypt.

- You will see it, Memnet. You will see him walk with his head among the eagles. And you will serve him as you serve me.

- Fill the ark with water. Sink it into silence.

- Raise your hands, Memnet. What you have buried in the Nile shall remain buried in your heart. Swear it.

- I will be silent.

- The day you break that oath will be the last your eyes shall ever see.

- You will be the glory of Egypt, my son. Mighty in words and deeds. Kings shall bow before you. Your name will live when the pyramids are dust.

- And because I drew you from the water, you shall be called Moses. Moses! Moses!

- He proclaims his coming from afar, does he not, my son?

- Such favor with the people can be dangerous, Great Sethi.

- To whom, Ramses? To me or to you?

[...]