Hebrews 10:19-20

Since, then, we have a cheerful confidence, brothers, to enter into the Holiest by the blood of Jesus,

Revelation 11:19

Then the temple of God in heaven was opened, and the ark of his covenant was seen inside his sanctuary; and there followed lightnings and voices and thunders, and an earthquake, and great hail.

Treasury of Scripture Knowledge

Summary

But they shall not go in to see when the holy things are covered, lest they die.

Bible References

They shall

Hebrews 10:19
Since, then, we have a cheerful confidence, brothers, to enter into the Holiest by the blood of Jesus,
Revelation 11:19
Then the temple of God in heaven was opened, and the ark of his covenant was seen inside his sanctuary; and there followed lightnings and voices and thunders, and an earthquake, and great hail.