Verily I say unto you To them all, what he had said before to Peter; (See Gill on Matthew 16:19): what is said here, refers to things and not persons, as there also.
16
"But what if he won't listen to you? Then take one or two others with you. Scripture says, 'Every matter must be proved by the words of two or three witnesses.'(Deuteronomy 19:15)
17
But what if he also refuses to listen to the witnesses? Then tell it to the church. And what if he refuses to listen even to the church? Then don't treat him as your brother. Treat him as you would treat an ungodly person or a tax collector.
18
"What I'm about to tell you is true. What you lock on earth will be locked in heaven. What you unlock on earth will be unlocked in heaven.
19
"Again, here is what I tell you. Suppose two of you on earth agree about anything you ask for. My Father in heaven will do it for you.
20
Where two or three people meet together in my name, I am there with them."