The verse is dealing with "concealing a transgression" by forgiving an offense for the sake of loving a brother and reconciliation. However, "he who repeats the matter" is seeking to stir up strife and cause division. Some examples would be when someone has sinned against you and you've forgiven them so you are no longer holding that sin over their head. However, others may continually bring up that sin and offense only to cause division and strife.