YOu can change the permissions. I don't think there is a way currently to Block them without going into the Server software code.
PHP: public function onCommandPreprocess(\pocketmine\event\player\PlayerCommandPreprocessEvent $event){ $command = explode(' ', strtolower($event->getMessage())); if($command[0] === '/plugins'){ $event->setCancelled(); }} This should be in the facepalm section. Another (better) way is to use permissions.
you can block without going into the true source code as leet.cc has a plugin named BlockedCommands as you can block and unblock commands therefore showing we can do it without modifying pocketmines true source code
Sorry my bad. I forgot explode returns an array. This is the fixed and working one: PHP: public function onCommandPreprocess(\pocketmine\event\player\PlayerCommandPreprocessEvent $event){ $command = explode(' ', strtolower($event->getMessage())); if($command[0] === '/plugins'){ $event->setCancelled(); }}