Deuteronomy 19:15
A lone witness is not sufficient to establish any wrongdoing or sin against a man, regardless of what offense he may have committed. A matter must be established by the testimony of two or three witnesses.

Numbers 35:30
If anyone kills a person, the murderer is to be put to death on the testimony of multiple witnesses. But no one is to be put to death based on the testimony of a lone witness.

Matthew 18:16
But if he will not listen, take one or two others along, so that 'every matter may be established by the testimony of two or three witnesses.'

John 8:17, 18
Even in your own Law it is written that the testimony of two men is valid. . . .

2 Corinthians 13:1
This is the third time I am coming to you. "Every matter must be established by the testimony of two or three witnesses."

1 Timothy 5:19
Do not entertain an accusation against an elder, except on the testimony of two or three witnesses.

Hebrews 10:28
Anyone who rejected the Law of Moses died without mercy on the testimony of two or three witnesses.