Philo The Decalogue 1:46
45 And the people stood by, having kept themselves clean from all connection with women, and having abstained from all pleasures, except those which arise from a participation in necessary food, having been purifying themselves with baths and ablutions for three days, and having washed their garments and being all clothed in the purest white robes, and standing on tiptoe and pricking up their ears, in compliance with the exhortations of Moses, who had forewarned them to prepare for the solemn assembly; for he knew that such would take place, when he, having been summoned up alone, gave forth the prophetic commands of God. 46 And a voice sounded forth from out of the midst of the fire which had flowed from heaven, a most marvellous and awful voice, the flame being endowed with articulate speech in a language familiar to the hearers, which expressed its words with such clearness and distinctness that the people seemed rather to be seeing than hearing it. 47 And the law testifies to the accuracy of my statement, where it is written, "And all the people beheld the voice most evidently." For the truth is that the voice of men is calculated to be heard; but that of God to be really and truly seen. Why is this? Because all that God says are not words, but actions which the eyes determine on before the ears. 48 It is, therefore, with great beauty, and also with a proper sense of what is consistent with the dignity of God, that the voice is said to have come forth out of the fire; for the oracles of God are accurately understood and tested like gold by the fire.
Acts 2:3
1 Now when the day of Pentecost had come, they were all together in one place. 2 Suddenly a sound like a violent wind blowing came from heaven and filled the entire house where they were sitting. 3 And tongues spreading out like a fire appeared to them and came to rest on each one of them. 4 All of them were filled with the Holy Spirit, and they began to speak in other languages as the Spirit enabled them. 5 Now there were devout Jews from every nation under heaven residing in Jerusalem. 6 When this sound occurred, a crowd gathered and was in confusion because each one heard them speaking in his own language. 7 Completely baffled, they said, “Aren’t all these who are speaking Galileans?
Notes and References
"... In this regard, Philo’s first-century description of God’s appearance at Sinai may not be a haphazard parallel: God’s revelation came “from heaven” like a “flame”, which became “a dialect” and caused “amazement” (Decalogue 46, a parallel noted by several commentators; see some identical wording in Acts 2:3, 6-7). Philo’s rendering is not that far removed from the account in the book of Exodus, where “voices” is closely linked to “torches” of fire: “all the people saw the voices and the torches” (Exodus 20:18; “torches” of fire also describe a heavenly temple scene in Ezekiel 1:13). Later Judaism also preserves references saying that God’s voice in giving the law at Sinai was like fire ..."
Beale, G. K. Handbook on the New Testament Use of the Old Testament: Exegesis and Interpretation (p. 125) Baker Academic, 2012