In our days it is even exceedingly rare to hear a voice speak from heaven, but it seems to have been more common in the days of the Apostles. Talmudic literature offers several anecdotes of “a voice from heaven” speaking during the late Second Temple Era.
The Hebrew term for the heavenly voice, bat kol, literally means “daughter of a voice,” a way to describe an echo or reverberation. The Talmud uses the term to refer to a voice heard from an unseen speaker. The Apostle Paul heard a voice from heaven speak to him as did the writer of the book of Revelation. The Gospels record three incidents involving a voice speaking from heaven: the voice at the Jordan, the voice at the triumphal entry (John 12:29), and the voice on the mount of the Transfiguration.
The voice from heaven that spoke at the Transfiguration repeated the same message which the Master heard at the time of His immersion in the Jordan. In that instance, the voice addressed Yeshua directly, saying, “You are my Son …” On the high mountain, the voice addressed the disciples, “This is My beloved son …”, and the message came with the addition imperative, “Listen to Him!”
This is My beloved Son, with whom I am well-pleased; listen to Him! (Matthew 17:5)
The mysterious declaration “This is my beloved son” alludes directly to Psalm 2 where the LORD tells His anointed one (messiah), “You are my Son; today I have begotten You” (Psalm 2:7). The sages regarded Psalm 2 as a psalm about the Messiah, and they frequently employed the psalm to provide proof texts regarding the Messiah.
The words “with whom I am well-pleased” (Matthew 17:5; 2 Peter 1:17) directly allude to the messianic servant song of Isaiah 42:1: “Behold, My Servant, whom I uphold; My chosen one in whom My soul delights. I have put My Spirit upon Him …” (Isaiah 42:1). “With whom I am well-pleased” is a Greek equivalent for the Hebrew idiom, “In whom My soul delights.” By alluding to Isaiah 42:1, the first of the servant songs, the voice from heaven identifies Yeshua of Nazareth as the subject of all of Isaiah’s “Servant of the LORD” prophecies which culminate in the suffering servant of Isaiah 53.
The voice directed the disciples to “listen to Him,” alluding to the prophecy of the prophet like Moses. In Deuteronomy 18 Moses told the children of Israel that the LORD would one day raise a prophet like him from among the Jewish people. The Torah says, “You shall listen to him” (Deuteronomy 18:15). The heavenly voice identified Yeshua as the prophet like unto Moses to whom the people must listen. (Click to Source)