This, Alexander, is the legend of the Gordian knot.

5 seconds sound clip from the Alexander the Great (1956) movie soundboard.

You can hear this line at 01:26:14 in the Blu-ray version of the movie.

Quote context

[...]

- How will you celebrate this victory, Alexander?

- At Chaeronea your father celebrated his by dancing over the dead bodies of Greeks who fought for freedom.

- Freedom? You fight for pay! Earn it!

- Then let it be to the death.

- Of all the Greeks who fought at Granicus, no one escaped alive.

- This, Alexander, is the legend of the Gordian knot.

- In many years past, when we were sorely pressed, it was said that a king would arrive in a village cart who would help us and become our ruler.

- This came about. And the king was Gordius, who left his cart here, as it stands, with this message: That anyone who could unravel this knot would become ruler of Asia.

- Many have tried. All have failed.

- Ephesus, Sardis, Helicarnassus. He is cutting off the Persian fleet from every port along the coast of Asia Minor.

[...]