Matthew 18:16

but if he do not listen, take with thee one or two more; that by the mouth of two or three witnesses every word may be established.

John 8:17

Moreover, it is written in your law, that the witness of two men is true.

2 Corinthians 13:1

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

1 Timothy 5:19

Against an elder receive not an accusation without two or three witnesses.

Hebrews 10:28

He that hath set at nought the law of Moses dieth without mercy under two or three witnesses;

1 John 5:7-8

For there are three that bear witness,

Revelation 11:3

And I will give power 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
Moreover, it is written in your law, that the witness of two men is true.
2 Corinthians 13:1
This is the third time I am coming to you. In the mouth of two or three witnesses shall every word be established.
1 Timothy 5:19
Against an elder receive not an accusation without two or three witnesses.
Hebrews 10:28
He that hath set at nought the law of Moses dieth without mercy under two or three witnesses;
1 John 5:7
For there are three that bear witness,
Revelation 11:3
And I will give power to my two witnesses, and they shall prophesy a thousand two hundred and sixty days, clothed in sackcloth.