Revelation 14: 1 - 5
1 Then I looked, and lo, on Mount Zion stood the Lamb, and with him a hundred and forty-four thousand who had his name and his Father's name written on their foreheads.
2 And I heard a voice from heaven like the sound of many waters and like the sound of loud thunder; the voice I heard was like the sound of harpers playing on their harps,
3 and they sing a new song before the throne and before the four living creatures and before the elders. No one could learn that song except the hundred and forty-four thousand who had been redeemed from the earth.
4 It is these who have not defiled themselves with women, for they are chaste; it is these who follow the Lamb wherever he goes; these have been redeemed from mankind as first fruits for God and the Lamb,
5 and in their mouth no lie was found, for they are spotless.

EWTN