package com.example.groupid.samplebukkitplugin;

import org.bukkit.command.Command;
import org.bukkit.command.CommandExecutor;
import org.bukkit.command.CommandSender;

import com.google.common.base.Joiner;

/*
 * This is a sample CommandExectuor
 */
public class SampleBukkitPluginCommandExecutor implements CommandExecutor {
    private final SampleBukkitPlugin plugin;

    /*
     * This command executor needs to know about its plugin from which it came from
     */
    public SampleBukkitPluginCommandExecutor(SampleBukkitPlugin plugin) {
        this.plugin = plugin;
    }

    /*
     * On command set the sample message
     */
    public boolean onCommand(CommandSender sender, Command command, String label, String[] args) {
        if (sender.hasPermission("sample.message") && args.length > 0) {
            this.plugin.getConfig().set("sample.message", Joiner.on(' ').join(args));
            return true;
        } else {
            return false;
        }
    }

}

@@ -743,54 +743,58 @@
     
-if (sender.hasPermission(%22sample.message%22) && 
+// Permission check is done by Bukkit%0A        if (
 args

Remove redundent permission check