Matthew 27:52

and the tombs were opened; and many bodies of the saints who had fallen asleep were raised;

1 Corinthians 15:20

But now hath Christ been raised from the dead, the First fruit of those who have fallen asleep.

1 Thessalonians 4:14

for, if we believe that Jesus died and rose again, so also those who fell asleep in Jesus will God bring with Him.

John 5:25-29

Verily, verily, I say to you, the hour is coming, and now is, when the dead will hear the voice of the Son of God, and those having heard shall live.

Acts 7:60

And, kneeling down, he cried with a loud voice, "Lord, lay not this sin to them!" And, having said this, he fell asleep.

1 Corinthians 11:30

For this cause, many among you are weak and sick, and not a few sleep.

1 Corinthians 15:51

Behold, I tell you a mystery: we shall not all sleep, but we shall all be changed,

1 Thessalonians 5:10

Who died for us, that, whether we watch or sleep, we may live together with Him.

Treasury of Scripture Knowledge

Summary

And the graves were opened; and many bodies of the saints which slept arose,

General references

Bible References

Many

John 5:25
Verily, verily, I say to you, the hour is coming, and now is, when the dead will hear the voice of the Son of God, and those having heard shall live.
1 Corinthians 15:20
But now hath Christ been raised from the dead, the First fruit of those who have fallen asleep.

Slept

1 Corinthians 11:30
For this cause, many among you are weak and sick, and not a few sleep.
1 Corinthians 15:51
Behold, I tell you a mystery: we shall not all sleep, but we shall all be changed,
1 Thessalonians 4:14
for, if we believe that Jesus died and rose again, so also those who fell asleep in Jesus will God bring with Him.
1 Thessalonians 5:10
Who died for us, that, whether we watch or sleep, we may live together with Him.

General references

Mark 15:38
And the veil of the temple was rent in two from the top to the bottom.
Luke 19:40
And, answering, He said, "I tell you that, if these shall be silent, the stones will cry out!"