Matthew 18:16

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

John 8:17

And it is written in your own law, that the testimony of two persons is valid.

2 Corinthians 13:1

This, I say, is the third time I am coming to you: and at the mouth of two or three witnesses shall every word be established.

1 Timothy 5:19

Receive not an accusation against an elder, unless from two or three witnesses.

Hebrews 10:28

If any one that violateth the law of Moses, dieth without mercy under two or three witnesses,

1 John 5:7-8

Yea there are three that bear witness, the Spirit, and the water, and the blood:

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
And it is written in your own law, that the testimony of two persons is valid.
2 Corinthians 13:1
This, I say, is the third time I am coming to you: and at the mouth of two or three witnesses shall every word be established.
1 Timothy 5:19
Receive not an accusation against an elder, unless from two or three witnesses.
Hebrews 10:28
If any one that violateth the law of Moses, dieth without mercy under two or three witnesses,
1 John 5:7
Yea there are three that bear witness, the Spirit, and the water, and the blood:
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.