Matthew 18:16

if he may not hear thee, take with thyself one or two, in order that in the mouth of two or three witnesses the word may stand.

John 8:17

And it has been written in our law, that the testimony of two men is true.

2 Corinthians 13:1

This the third time I am coming to you: in the mouth of two or three witnesses every word shall be established.

1 Timothy 5:19

Bring not an accusation against an elder, except before two or three witnesses.

Hebrews 10:28

The one having rejected the law of Moses dies without mercy before two or three witnesses:

1 John 5:7-8

Because there are three who are bearing witness,

Revelation 11:3

And I will give to my two witnesses, and they shall prophesy a thousand two hundred and sixty days, clothed in sackcloth.

Treasury of Scripture Knowledge

Summary

But if he will not hear thee, then take with thee one or two more, that in the mouth of two or three witnesses every word may be established.

Bible References

That in

John 8:17
And it has been written in our law, that the testimony of two men is true.
2 Corinthians 13:1
This the third time I am coming to you: in the mouth of two or three witnesses every word shall be established.
1 Timothy 5:19
Bring not an accusation against an elder, except before two or three witnesses.
Hebrews 10:28
The one having rejected the law of Moses dies without mercy before two or three witnesses:
1 John 5:7
Because there are three who are bearing witness,
Revelation 11:3
And I will give to my two witnesses, and they shall prophesy a thousand two hundred and sixty days, clothed in sackcloth.