Wait....

what the fuck?

src/main/java/ru/tehkode/modifyworld/handlers/PlayerListener.java

@@ -175,6 +175,23 @@ public class PlayerListener extends ModifyworldListener {
         this.checkPlayerInventory(player);
     }
 
+    @EventHandler(priority = EventPriority.LOW)
+    public void onPlayerInventoryEvent(InventoryClickEvent event) {
+        ItemStack item = event.getCursor();
+
+        if(item == null || item.getType() == Material.AIR || event.getSlotType() != InventoryType.SlotType.QUICKBAR) {
+            return;
+        }
+
+        Player player = (Player)event.getWhoClicked();
+
+        int targetSlot = player.getInventory().getHeldItemSlot();
+
+        if(event.getSlot() == targetSlot &&  permissionDenied(player, "modifyworld.items.hold", item)) {
+            event.setCancelled(true);
+        }
+    }
+
     @EventHandler(priority = EventPriority.LOW)
     public void onPlayerInteractEntity(PlayerInteractEntityEvent event) {
         if (this.checkItemUse) {