One of the attributes that must be denied of the One God is sensory visibility: the Lord cannot be apprehended by the five senses. So how did Moses (AS) hear God’s voice, and how did God speak to him directly?
How Did Moses Hear the Voice of God?
The essence and first answer at a glance (60-word summary)
The Lord’s speech consists of originated utterances and creative words brought into being by the command “Be, and it is.” It is unlike the speech of created beings. In the conversation with Moses, the angel of revelation played no part; the divine will was conveyed to him in the form of words. This speech is not like speaking with a mouth and tongue.
Answer by Master Ali Saei (Abdullah Meshkat)
Teacher and researcher in the intellectual tradition of wisdom and the Ahl al-Bayt | Soroush Bamdadān Cultural CenterThe speech of the Lord is among the originated acts of the Almighty Creator. It is a particular form of divine communication: speech brought into being by the command «کن فیکون». Put simply, God creates speech; His speaking to Moses (AS) was itself an act of creation. In truth, when God spoke to Moses, the angel of revelation had no role in conveying the message of the Most High. God willed, and His will was conveyed to Moses (AS) in the form of words.
نساء: 164
و رسلا قد قصصناهم علیک من قبل و رسلا لم نقصصهم علیک و کلم الله موسى تکلیما
And We sent messengers whose stories We have already told you, and others whose stories We have not told you; and God spoke directly to Moses.
It is narrated from Safwan ibn Yahya that he said: Abu Qurra, the hadith scholar, asked al-Rida (AS), “May God make me your ransom, tell me about God’s speech to Moses. In what language did God speak to him—Syriac or Hebrew?” Abu Qurra pointed to his own tongue and said, “I am asking you about this tongue.” Abu al-Hasan (AS) replied, “Glory be to God! God is far above what you say. God forbid that He resemble His creation or speak as they speak. Blessed and Exalted is He: nothing is like Him, nor is there any speaker or doer like Him.”
“How, then?” Abu Qurra asked.
“The Creator’s speech to a creature is unlike one creature’s speech to another,” he replied. “He does not utter words with a mouth and tongue, but says to it, ‘Be,’ and it comes to be by His will. What He said to Moses, in the form of commands and prohibitions, came about without any hesitation in Himself.”
Biḥār al-anwār (Beirut edition), vol. 4, p. 152
Abu al-Hasan al-Rida (AS) said that the Creator’s speech to a creature does not involve God, the Preserver, articulating words with a mouth and tongue, or speaking and expressing Himself. Rather, He says, «کن فیکون».
That is, as soon as He utters this word and wills the command, the thing comes into manifest existence. Thus, when God, the Most Holy, addressed and spoke with the holy prophet Moses (AS), giving him commands and prohibitions without any hesitation in Himself, this—and nothing else—was the manner in which it took place.
Al-Iḥtijāj ʿalā ahl al-lijāj (by al-Ṭabrisī) / translation and commentary by Ghaffari, vol. 4, p. 64