Charles Spurgeon Commentary Matthew 18:16

"But if he hear [thee] not, take with thee one or two more, that at the mouth of two witnesses or three every word may be established." — Matthew 18:16 (ASV)

If the brother has trespassed very badly, he will probably be sullen or impertinent, and he will not listen to you. Therefore, do not give up on him. Persevere in seeking peace. Support your own pleas with companionship; take one or two more with you. Possibly the offender may pay attention to what is said by the other brethren, although he may be prejudiced against you, or he may give weight to a united appeal that he might not feel if the complaint came from only one person.

By calling in worthy arbitrators, you give the offender a fairer opportunity to set himself right. This time, let us hope, the brother will be won over. But if not, you will have secured yourself against misrepresentation, that in the mouth of two or three witnesses every word may be established. It is by misquoting words that quarrels are provoked, and it is a great thing to have the means to correct false reports. Although it is very unwise to interfere in quarrels, yet from this text it is clear that we should be willing to be one of the two or three who assist in settling a difference.