Be it known, the province of Mexico known as Texas has shown itself to be an active in treasonous revolt against the rule of Generalissimo Santa Anna.

10 seconds sound clip from the The Alamo (1960) movie soundboard.

You can hear this line at 01:18:50.640 in the Blu-ray version of the movie.

Quote context

[...]

- Something's stirring in town!

- Ladies will take cover, please. Men, to your battle positions!

- Captain Dickinson? Are your men disposed?

- At their posts, sir.

- No one will fire unless I so order! Those people are under the protection of a flag of truce!

- From the headquarters of Generalissimo Antonio Lopez de Santa Anna, absolute ruler of Mexico, to the rebel commander who deems himself in command of the rebels occupying the mission.

- Be it known, the province of Mexico known as Texas has shown itself to be an active in treasonous revolt against the rule of Generalissimo Santa Anna.

- The Generalissimo, in his kindness, issues the following order.

- All occupants of the mission will leave at once, leaving all arms and ammunition behind.

- If this order is not followed with dispatch, the Generalissimo will reduce the mission by assault. There will be no quarter given.

(Cannon fire)

[...]