Revelation 21:4

He will wipe every tear from their eyes. Death shall be no more; nor sorrow, nor wail of woe, nor pain; for the first things have passed away."

Revelation 7:15-17

For this reason they stand before the very throne of God, and render Him service, day after day and night after night, in His sanctuary, and He who is sitting upon the throne will shelter them in His tent.

Treasury of Scripture Knowledge

Summary

Thy sun shall no more go down; neither shall thy moon withdraw itself: for the LORD shall be thine everlasting light, and the days of thy mourning shall be ended.

General references

Bible References

The days

Revelation 7:15
For this reason they stand before the very throne of God, and render Him service, day after day and night after night, in His sanctuary, and He who is sitting upon the throne will shelter them in His tent.
Revelation 21:4
He will wipe every tear from their eyes. Death shall be no more; nor sorrow, nor wail of woe, nor pain; for the first things have passed away."

General references

1 Corinthians 13:10
but when the perfect state of things is come, all that is imperfect will be brought to an end.