Zohar 3:265a

Jewish Mysticism
R. Shim’on said- If people only knew the words of Torah then they would comprehend that there is no word or letter in the Torah that does not contain supernal, precious secrets. Come and see- it is written, “Moses spoke and God answered him with a voice” (Exod. 19-19). It has been taught [b. Berakhot 45a ]- what is [the meaning of] “with a voice”? With the voice of Moses. This is correct, the voice of Moses precisely (dayka), the voice to which he was attached and through which he was superior to all other prophets.

Translated by Elliot Wolfson in- “Beautiful Maiden Without Eyes- Peshat and Sod in Zoharic Hermeneutics.” In The Midrashic imagination – Jewish exegesis, thought, and history. Edited by Michael Fishbane, Albany – State University of New York Press, 1993, pp. 155-203.