Matthew 18:15-17 NASB1995
“If your brother sins, go and show him his fault in private; if he listens to you, you have won your brother. But if he does not listen to you, take one or two more with you, so that BY THE MOUTH OF TWO OR THREE WITNESSES EVERY FACT MAY BE CONFIRMED. If he refuses to listen to them, tell it to the church; and if he refuses to listen even to the church, let him be to you as a Gentile and a tax collector.
NASB1995: New American Standard Bible - NASB 1995