‘And I heard a voice (sound) from heaven like the voice (sound) of many waters and like the voice (sound) of a great thunder, and the voice (sound) which I heard was like the voice (sound) of harpists harping with their harps, and they sing as it were a new song before the throne and before the four living creatures and the elders, and no one could learn the song except the one hundred and forty four thousand, those who had been purchased out of the earth.'
The voice like the voice of many waters was the voice of the Son of Man in Revelation 1:15, the voice like a great thunder was the voice of the living creature in Revelation 6:1, the harpists harping with their harps are the twenty four elders in Revelation 5:8. Later also the voice as the sound of many waters and the voice of mighty thunders is the voice of a great heavenly multitude (Revelation 19:6) who celebrate the marriage of the Lamb and His bride. Thus the mighty ones of Heaven unite in their welcome of these redeemed people. This forms the swelling background to the song of the one hundred and forty four thousand.
‘And they sing as it were a new song before the throne and before the four living creatures and the elders.' This is the song of the redeemed celebrating the name which no one could know except those who received it (Revelation 2:17). They sing ‘as it were a new song' because they have now been raptured or resurrected and stand in their new spiritual bodies before God. It is the new song of Revelation 5:9 and yet it is freshly new for it is now sung by those who have actually experienced redemption. They glory in what has been done for them by Him who purchased them out of the earth.
Alternately it may be a song sung by the heavenly multitudes to welcome them into Heaven, then ‘no man could learn the song' refers to the fact that it is for the redeemed and the redeemed alone. They alone are recipients of the welcome.
‘No one could learn the song except the one hundred and forty four thousand'. ‘No one' must refer to those who dwell on earth for it is sung before the living creatures and the elders so that they learn the song. Alternately it may signify that no one else can really know the song fully because they have not experienced it in full. Indeed both ideas may be in mind. What a wonderful song of triumph it must be. Their sufferings and trials are behind them and they are now to share Heaven with their Lord and Saviour Who has prepared a place for them (John 14:2) and to receive their rewards at the Judgment Seat of Christ (Romans 14:10; 1 Corinthians 3:12-15; 1 Corinthians 4:5; 2 Corinthians 5:10). But they are not thinking of this but of their Saviour and Redeemer Who bought them with His own blood.