Matthew 18:16

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

John 8:17

Now even in your law it is written, that the testimony of two men is true.

2 Corinthians 13:1

THIS third time I am coming to you: by the mouth of two or three witnesses shall every charge be established.

1 Timothy 5:19

Against a presbyter receive not an accusation, except it be from two or three witnesses.

Hebrews 10:28

Any man who treated the law of Moses with neglect, was put to death, without mercy, on the deposition of two or three witnesses:

1 John 5:7-8

For they are three who bear witness in heaven, the Father, the Word, and the Holy Spirit, and these, even the three, are one.

Revelation 11:3

And I will give charge 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
Now even in your law it is written, that the testimony of two men is true.
2 Corinthians 13:1
THIS third time I am coming to you: by the mouth of two or three witnesses shall every charge be established.
1 Timothy 5:19
Against a presbyter receive not an accusation, except it be from two or three witnesses.
Hebrews 10:28
Any man who treated the law of Moses with neglect, was put to death, without mercy, on the deposition of two or three witnesses:
1 John 5:7
For they are three who bear witness in heaven, the Father, the Word, and the Holy Spirit, and these, even the three, are one.
Revelation 11:3
And I will give charge to my two witnesses, and they shall prophesy a thousand two hundred and sixty days, clothed in sackcloth.