זוהר שמות — דף כו ע”א

During all the time Moses was in Egypt, he did not speak any true speech, because the Word (Dibur) was in exile. When the Shekhinah came out of exile, the Voice joined the Word, and the Word led Israel. The redemption is the beginning of the union of Voice and Word. The revelation at Sinai is the apex of the unity of Voice and Word.