1 John 5:7-8

And it is the Spirit who testified; because the Spirit is the truth.

Revelation 11:3

And I will give to my two witnesses commission, 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

1 John 5:7
And it is the Spirit who testified; because the Spirit is the truth.
Revelation 11:3
And I will give to my two witnesses commission, and they shall prophesy a thousand two hundred and sixty days, clothed in sackcloth.