Revelation 14:1-3

Young's Literal Translation

14 And I saw, and lo, a Lamb having stood upon the mount Sion, and with him an hundred forty-four thousands, having the name of his Father written upon their foreheads;

² and I heard a voice out of the heaven, as a voice of many waters, and as a voice of great thunder, and a voice I heard of harpers harping with their harps,

³ and they sing, as it were, a new song before the throne, and before the four living creatures, and the elders, and no one was able to learn the song except the hundred forty-four thousands, who have been bought from the earth;