Matthew 18:16
King James Version
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.
Matthew 18:16 in context
Even so it is not the will of your Father which is in heaven, that one of these little ones should perish.
Moreover if thy brother shall trespass against thee, go and tell him his fault between thee and him alone: if he shall hear thee, thou hast gained thy brother.
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.
And if he shall neglect to hear them, tell it unto the church: but if he neglect to hear the church, let him be unto thee as an heathen man and a publican.
Verily I say unto you, Whatsoever ye shall bind on earth shall be bound in heaven: and whatsoever ye shall loose on earth shall be loosed in heaven.