Revelation 14:1-3

1I looked, and the lamb was standing on Mount Zion. There were 144,000 people with him who had his name and his Father’s name written on their foreheads.

2Then I heard a sound from heaven like the noise of raging water and the noise of loud thunder. The sound I heard was like the music played by harpists.

3They were singing a new song in front of the throne, the four living creatures, and the leaders. Only the 144,000 people who had been bought on earth could learn the song.