1 Peter 3:19

By which, also, he made proclamation to the spirits in prison,

1 Peter 4:6

For, to this end of the gospel was preached to the dead, that they might, indeed, be judged according to men in the flesh, but live according to God in the spirit.

Revelation 19:10

And I fell before his feet to worship him; and he said to me, See you do it not: I am a fellow-servant with you, and with your brethren who keep the testimony of Jesus. Worship God; for the testimony of Jesus is the spirit of prophecy.

Revelation 20:7

And when the thousand years shall be accomplished, Satan shall be loosed from his confinement;

Treasury of Scripture Knowledge

Summary

By which also he went and preached unto the spirits in prison;

Bible References

By which

1 Peter 4:6
For, to this end of the gospel was preached to the dead, that they might, indeed, be judged according to men in the flesh, but live according to God in the spirit.
Revelation 19:10
And I fell before his feet to worship him; and he said to me, See you do it not: I am a fellow-servant with you, and with your brethren who keep the testimony of Jesus. Worship God; for the testimony of Jesus is the spirit of prophecy.

In

Revelation 20:7
And when the thousand years shall be accomplished, Satan shall be loosed from his confinement;