זוהר שמות — דף ריה ע”א

When the sages brought the words before Rabbi Shimon, he opened on the verse: the path of the righteous is like the bright light that grows until the day is established. The orach (path) is a way first opened by the righteous, where the Shekhinah walks and celestial chariots come to hear their words. The derech (road) is open to all, even the wicked. Moses is like the sun, Joshua like the moon that fills with the sun's light. The moon reaches its completeness when it receives the light of the supernal sun.