Solemnity of All Saints - First reading of The Mass

Apocalypse 7:2-4,9-14 ©
I, John, 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.’ Then I heard how many were sealed: a hundred and forty-four thousand, out of all the tribes of Israel.
After that I saw a huge number, impossible 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 aloud, ‘Victory 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 animals, prostrated themselves before the throne, and touched the ground with their foreheads, worshipping God with these words, ‘Amen. Praise and glory and wisdom and thanksgiving and honour and power and strength to our God for ever and ever. Amen.’
One of the elders then spoke, and asked me, ‘Do you know who these people are, dressed in white robes, and where they have come from?’ I answered him, ‘You can tell me, my lord.’ Then he said, ‘These are the people who have been through the great persecution, and because they have washed their robes white again in the blood of the Lamb.’