After this I looked, and there was a great crowd that no one could number. They were from every nation, tribe, people, and language. They were standing before the throne and before the Lamb. They wore white robes and held palm branches in their hands.
References for Revelation 7:9
They cried out with a loud voice: "Victory belongs to our God who sits on the throne, and to the Lamb."
All the angels stood in a circle around the throne, and around the elders and the four living creatures. They fell facedown before the throne and worshipped God,
saying, "Amen! Blessing and glory and wisdom and thanksgiving and honor and power and might be to our God forever and always. Amen."
Then one of the elders said to me, "Who are these people wearing white robes, and where did they come from?"
I said to him, "Sir, you know." Then he said to me, "These people have come out of great hardship. They have washed their robes and made them white in the Lamb's blood.
This is the reason they are before God's throne. They worship him day and night in his temple, and the one seated on the throne will shelter them.
They won't hunger or thirst anymore. No sun or scorching heat will beat down on them,
because the Lamb who is in the midst of the throne will shepherd them. He will lead them to the springs of life-giving water, and God will wipe away every tear from their eyes."
References for Revelation 7:17