Deuteronomy 17:6 -- At the mouth of two witnesses, or three witnesses, shall he that is worthy of death be put to death; but at the mouth of one witness he shall not be put to death.

Deuteronomy 19:15 -- One witness shall not rise up against a man for any iniquity, or for any sin, in any sin that he sinneth: at the mouth of two witnesses, or at the mouth of three witnesses, shall the matter be established.

Matthew 18:16 -- 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.

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, but before two or three witnesses.

Hebrews 10:28 -- He that despised Moses' law died without mercy under two or three witnesses.