It is not Pharaoh who yields to the slave, but his counselors.
6 seconds sound clip from the The Ten Commandments (1956) movie soundboard.
You can hear this line at 02:35:46.474 in the Blu-ray version of the movie.
Quote context
[...]
- Will my father free the slaves?
- Can taxes be collected from dead cattle and blighted harvests?
- Does fear rule Egypt, or do I?
- We fear no army of the Earth, but can we fight plagues with swords?
- It is not Pharaoh who yields to the slave, but his counselors.
- I have summoned Moses at your request.
- People will bless you, great one.
- Does the world bow to an empty throne?
- Empty?
- Does a Pharaoh harden his heart against his son?
- If you let the Hebrews go, who will build his cities?
[...]