As the first puzzle in the Sphinx, you will reach a series of dashes on the wall that look like this ( -|-- ). They represent the path stones in the Scorpion chamber. When they are all horizontal (----), you will walk OVER the Sphinx's trap.
If you click on a line, the other three rotate by 90°. So press the first, third, and fourth lines (-) exactly once and they will all line up (----). This allows you to take the upper path and avoid the scorpion.