Revelation 7, 2-4.9-14
Then I saw another angel rising where the sun rises, carrying the seal of the living God; he called in a powerful voice to the four angels whose duty was to devastate land and sea,
'Wait before you do any damage on land or at sea or to the trees, until we have put the seal on the foreheads of the servants of our God.'
And I heard how many had been sealed: a hundred and forty-four thousand, out of all the tribes of Israel.
After that I saw that there was a huge number, impossible for anyone to count, of people from every nation, race, tribe and language; they were standing in front of the throne and in front of the Lamb, dressed in white robes and holding palms in their hands. They shouted in a loud voice,
'Salvation to our God, who sits on the throne, and to the Lamb!'
And all the angels who were standing in a circle round the throne, surrounding the elders and the four living creatures, prostrated themselves before the throne, and touched the ground with their foreheads, worshipping God
with these words: Amen. Praise and glory and wisdom, thanksgiving and honour and power and strength to our God for ever and ever. Amen.
One of the elders then spoke and asked me, 'Who are these people, dressed in white robes, and where have they come from?'
I answered him, 'You can tell me, sir.' Then he said, 'These are the people who have been through the great trial; they have washed their robes white again in the blood of the Lamb.